Well, right off the bat, I should point out that the music in this game is utterly fantastic, taking full advantage of the system' hardware to create a soundtrack that, while retaining that distinct Genesis sound, nevertheless manages to rival the likes of many greats on the competing SNES platform. Proof that a system's hardware capabilities take a back seat to compositional skill. It's also something that unfortunately gets lost with emulation, as no emulator I've seen perfectly captures the distinct "twang" of the original Genesis sound chip. If at all possible, I would recommend checking this one out in its original format so that you get the full experience.
And now for a bit on the game itself. Originally the game was slated for release on the Sega CD and would have presumably utilized its video and audio capabilities to deliver an experience on par with the Lunar titles. However, as the Sega CD platform proved to be unpopular, development eventually shifted to the Sega Genesis, and the project was reworked to match the smaller scale of the medium. There are still elements of its CD origins in the final game, though, as most of the key plot scenes are told through manga-styled panels:
...Which lends it a nice cinematic feel despite the obvious space limitations that cartridges had in those days.
The story and gameplay also underwent heavy retooling, as early screenshots of the game show it having first person dungeons like the original Phantasy Star. The working title for the Sega CD version was "the return of Alis", hinting that the heroine of the original game would return as well (which would coincide with the plot of one of the obscure spinoff games on the Game Gear). Phantasy Star 1's heroine does not feature prominently in the final game's story, though she does make a "return" of sorts, as we'll see late in the game.
Our story opens in the town of Aiedo, with hunter Alys Brangwin (not to be confused with Alis) and her partner Chaz departing for the town of Piata to investigate some strange happenings. Apparently monsters have begun to appear in the university's basement and the principal of Piata Academy wants you to investigate, denying any knowledge of how they appeared there. On the way we also recruit Hahn, a student of the Academy who thinks the appearance of the monsters coincides with the disappearance of Professor Holt. After a bit of extortion on Alys' part, of course (a gag which repeats several times throughout the early stages of the game).
Spoony: A game with a sense of humor about its characters that doesn't just rely on dopey slapstick? Who'd have thought it?!
As for our characters:
Alys is by and large a physical fighter, wielding "Slashers" (bladed boomerangs) that hit all enemies on the field at once. They do less overall damage than a single-targeting weapon like a sword, but they also allow you to mop up weaker enemies in short order.
Chaz is the game's protagonist, and as such is pretty well-rounded in all respects, wielding swords or daggers (with the former being much stronger) and using a combination of attack, healing and support skills. He also gets some of the best combination techniques in the game, which I'll detail a bit more in a second.
Hahn is a bit more of a mage type, being fairly weak physically but wielding some pretty decent elemental techniques. Just keep him toward the back of the line and give him a shield to offset his weak defense and you've got a pretty solid character.
Something you'll notice right away is that this game moves very quickly in comparison to its predecessors, and in fact even in comparison to most RPGs to this day. I don't know if Sega was still trying to prove a point about their system's "blast processing" or what, but everything about Phantasy Star IV moves very quickly - the text scrolls very fast, combat animations are much more brief than most RPGs, random encounters are significantly less common than many RPGs, and even just walking around the world and town maps is very fluid. Despite this, it never feels like you're getting short-changed on content or longevity - there is easily as much content here as any other RPG of the era, it all just moves at a much faster clip. It lends itself to what is quite possibly the best pacing I've seen in any game of this type, and I won't lie, it does make going back to the earlier games in the franchise tougher when they move so slowly in comparison.
We fight our way through the basement and come to our first boss, a bizarre monster called "Igglanova" that continually spawns new monsters throughout the fight, as well as unleashing some nasty attacks of its own. However, if you keep killing the smaller enemies it spawns, it will never attack, so the fight becomes easy once you figure that out. Chaz and Hahn can easily wipe up the smaller enemies while Alys uses Vortex to deal heavy damage to Iggy.
The principal was clearly hiding something, as you find several cloning tubes down here specifically crafted to breed such monsters. When confronted about this, he reveals the truth - that the machines were brought from a place called "Birth Valley", a place which shows signs of an advanced civilization.
Spoony: This probably sounds familiar to you if you've played Phantasy Star II, as Mother Brain was engineering monsters for a mass genocide of the populace of Motavia.
Professor Holt's team embarked on a second journey for the valley, but never returned. As the principal was about to send out a rescue team, however, a man named Zio appeared and warned him to stay away from Birth Valley, turning the investigative team to stone to cement his threat. Hahn departs to investigate, but Alys agrees to come with him (for a price, of course).
Spoony: At this point, we might as well also talk about one of the game's defining features, that being its intricate skill system. Instead of just having a list of spells that cost TP, you also have character-specific "Skills" that can be used a set number of times between rests (and gain more charges as that character levels up).
Several abilities (both skills and techs) can also be combined together in "Combination techniques" that combine the properties of both and do more damage overall. For example, combining a Zan (wind) skill and a Foi (fire) skill will create the Firestorm technique, which hits all enemies on the field with both wind and fire damage. There are quite a few possible combinations for these and fourteen combination techniques overall, which lent a pretty unique twist to things. From a game that predated Chrono Trigger by about a year, no less.
Of course, being one of the first examples of this, it's also a bit unrefined in how it's executed. All of the skills involved in a combination must be cast consecutively - if an enemy or another teammate sneaks in a turn in the middle, you don't get the combo, which is a bit annoying when you have a fast character and a relatively slow one trying to combine their attacks. However, they do offset this slightly with the game's Macro system, which allows you to define your character's actions ahead of time and then use them in battle with only a couple button presses. Which is quite handy for pulling off combination moves as well as saving time on random battles.
We make our way to the town of Zema, whose entire populace has been turned to stone by Zio, including Professor Holt. Alys mentions that there is an ancient medicine named "Alshline" that may be able to cure them, but only Motavians have access to it.
Spoony: This is a slight throwback to Phantasy Star 1, but it was called "Alsulin" there due to an inconsistent translation. Which we'll see quite a few other examples of throughout this game. Not that I'm ripping on this game in particular - many other RPG franchises of the time had inconsistent translations between their games games (witness the early Final Fantasy titles and the Shining Force games for some other good examples). This was the era before translation teams comparing notes became the norm, I suppose.
To our latest end we head south to the Motavian village of Molcum, which is completely destroyed by the time we get there.
Spoony; And no, you can't just come down here early and get some Alshline that way - the entrance is barred by two racist guards who refuse to let any Parmanians in.
In the center of town is Rune, an old acquaintance of Alys' who claims that Molcum was destroyed by Zio. However, he does point you toward the town of Tonoe to the north and even joins the party for the trip, despite taking an instant dislike to Chaz.
Rune is the game's premier offensive mage, wielding many powerful attack techniques, mostly elemental themed. He also has a hefty supply of elemental skills, as well as two of the strongest offensive skills in the game in Efess (holy-elemental) and Legeon (non-elemental). He's also the first person to get a revival skill, oddly. He gets the usual tradeoff of low HP and defense, though you can exploit the game's dual-wielding system to offset that by equipping him with two shields and having him cast Flaeli as his basic attack - he gets enough charges with it to last through most every dungeon in the game.
It was also a pretty cool thing for the era to see characters with conflicting personalities - Rune and Chaz are at ends with one another throughout a good portion of the game, but still manage to maintain a working partnership. A nice contrast to games like Final Fantasy, where the characters pretty much have no real interaction at all outside of their introductory scenes...
We make our way up to Tonoe, where (after another humorous scene), Rune departs the party, setting off for parts unknown with the Motavian elder. In his place we get Gryz, the first (and only) playable Motavian character in the franchise. He's the only party member who wields axes and is honestly a pretty strong fighter in general, though his technique selection is lacking. He holds a personal grudge against Zio for destroying Molcum and joins you to get revenge, though that's not your stated goal as of yet...
After fighting our way through Tonoe's warehouse (stocked with surprisingly dangerous enemies), we get the Alshline and cure the people of Zema, which finally enables us to enter Birth Valley. True to what we've already seen, this is a monster breeding lab, apparently a remnant from the age of Mother Brain 1000 years prior (though thankfully lacking the confusing teleporter mazes of that era). However, it's not all flesh-eating horrors in here, as we soon meet Rika and her creator Seed.
Seed turns out to be an artificial intelligence running the plant, though he has since lost control of most of his functions, which in turn has led to the re-emergence of biological monsters. Other systems throughout Motavia have since gone awry as well, which will eventually lead to the planet's destruction if not stopped. Rika is a pet project of his, the end result of 1000 years of research on a prototype prior to the "Great Collapse", which Phantasy Star II fans will recognize.
Spoony: And for those who never played Phantasy Star II, that prototype was the villainous character "Neifirst" and her kind-hearted counterpart Nei.
Rika joins the team and Seed self-destructs in order to stop his systems from unleashing any more havoc on the people of Motavia, leading to another sad scene. However, he does give us a lead - the android Demi, currently held captive by Zio, may be able to prevent Motavia's control systems from collapsing and dooming the planet. However, to get to his fort, we end up having to take the long way around through Aiedo's cave system, as the road from Mile has been overtaken by quicksand.
On the way there are two optional sites - a town devastated by the impact of a satellite, and the crashed satellite itself. It turns out to be another story throwback, being one of the ships launched from Parma just before its destruction in Phantasy Star II. All the people aboard were killed by Dark Force, but the ship itself continued to operate, its orbit slowly decaying until it eventually crash-landed on the planet's surface.
Spoony: As fans of that game know, there were about 400 ships that escaped from Parma, but only two ended up surviving the wrath of Dark Force. Phantasy Star III takes place on one of those ships (the Alisa III), and depending upon the player's choices, the other surviving ship (the Neo Palm) may play a role in the story's events as well.
It may seem like a minor thing at a glance, but I love little details like this. They effectively pay tribute to the previous games in the series while also lending themselves to the franchise's lore. Of course, Phantasy Star is also unique among RPGs in that you witness a lot of its lore firsthand, instead of just being told about it after the fact.
Anyhow, back to the game itself. Rika is your primary healer for much of the game, possessing mostly restorative and support skills. She's also a relatively decent fighter - though her attacking skills are fairly limited overall, she can certainly hold her own and get quite a few kills in when nobody needs healing.
This is also your first chance to take part in some of the game's sidequests, accessible at the Hunter's Guild in Aiedo. These usually come in the form of optional boss battles or searching around the game world for something or other. Some have fairly minimal rewards (like finding a lost dog) while others are just good for a laugh (finding two missing girls and paying their bail, which happens to be the exact same price as the offered reward). The last one is definitely worth doing though, as it provides a bit more lore for the game as well as a particular character's best equipment.
Anyhow, after a moderately lengthy grinding session to get our parties' gear up to snuff, we make our way through the cave to the town of Kadary, where we find that Zio is not just an evil wizard. No sir, he has a full-fledged cult devoted to his worship, with his church also bearing the idol of a sinister (and familiar) looking entity. Yep, it's our old friend Dark Force.
Spoony: For those who haven't followed my previous nutshells, Dark Force has been a constant presence in the series since it began. He appeared as the final boss in the first game and the penultimate boss of the second, but his most prominent role was in the third game, where he was revealed to have set the Orakian and Layan factions against one another (which eventually culminates in his defeat once the truth is discovered). However, his presence has never been given any real explanation, save for a small hint in the third game that he is an "evil force from times beyond legend". The fourth game does finally offer some answers, but not before we confront him again. Several times, in fact!
We enter Zio's Fort, which is one of those gimmick dungeons that has a lot of paths and pits for you to explore, with several containing some pretty high-end gear but also forcing you to walk out an exit and go through the dungeon again from the start. A lot of it is good enough to be worth the extra effort, though, so c'est la vie.
We also encounter another miniboss in Juza, apparently one of Zio's underlings. He's not that tough, save for his rather nasty "Force Flash" attack that hits the entire party for a pretty good chunk of damage.
On the top floor we find Demi, who at first appears to be in a frame of a particularly bad hentai movie:
...But is quickly freed from any potential X-rated activity. However, Zio arrives shortly thereafter, giving off the typical mad cultist spiel about how he intends to destroy all life on Motavia to appease his lord Dark Force and giving the creepy Terminator glowy-eyes for good measure.
Spoony: Also punctuated with some really good, creepy music that just oozes menace, to say nothing of the incomparable sense of malice in his combat theme.
Zio proves to be a very dangerous opponent, shaking off any and all damage you throw at him as he prepares his ultimate attack - a bolt of pure dark energy called the Black Wave. He aims it at Chaz, but Alys leaps in front of him and takes the hit, becoming severely wounded for the effort and forcing the party to retreat.
Alys is left in dire straits as a result, with even the best healing techs available having absolutely no effect. In desperation, Chaz and company decide to set off to the east in search of Rune, hoping he'll have some way to counteract the Black Wave. Thankfully, Demi provides us a way to get across the quicksand barriers with the Land Rover, another Phantasy Star 1 throwback (as well as a unique take on the combat engine, as the vehicle has its own attack pool and even a different set of enemies to fight).
Demi herself is also quite a force to reckon with, filling the role of the party tank with her relatively high defense and powerful gun weapons. As an android she lacks any techniques, but she more than makes up for that with her set of Skills, which allow her to recover her own HP, launch fire-element "flares" at a single enemy, and stun mechs. She also gets the incredibly useful "Medic Power" ability, which restores HP to the entire party and cures all status effects (even death!). An optional dungeon along the way also allows you to get her ultimate attacking technique, Phononmezer, a powerful sonic attack that hits all enemies on the field.
She also has three odd traits as an android: She recovers HP with each step outside of battle, she cannot recover HP from Techniques (and must rely on either Repair Kits or her own Recover skill), and if she dies at any point during a battle, she will be revived afterwards with 1 HP. A pretty stark contrast from Phantasy Star III, were the two cyborg characters were functionally identical to anyone else in your party.
We venture to Ladea Tower and meet up with Rune halfway up, who has come here in search of the Psycho-Wand, a powerful artifact that can counteract Zio's tremendous powers.
Spoony: And possibly another subtle reference to Phantasy Star 1, though in that game you needed a "crystal" to avoid instant death at Lassic's hands.
We defeat another of Zio's flunkies (a monster called "Gy-Languiah" that is rather vulnerable to ice spells) and acquire the wand. However, Rika and Rune detect that something is amiss and the party rushes to Alys' side... just in time for her to perish before their eyes.
Spoony: It may be a genre cliche now, but having a prominent party member fall to the villain was still a pretty new and shocking thing to see in the mid-'90s. There is perhaps no more devastating example of it in that era than Alys Brangwin, however, as she was a well-defined and likeable character that you got legitimately invested in even over the short time you spend with her. A bit unrefined and greedy, certainly, but she did have a genuine personality, and even shows a surprisingly noble side when she sacrifices herself to save Chaz (a fact which he is pretty broken up about in the ensuing cinematics). A lot of gamers of that era were shedding tears over Aeris, but the genre faithful all knew where the real tragedy took place in the '90s!
After a brief funeral, we're on our way back to Zio's fort, dispelling the barrier and entering the tectonic control facility beneath his fortress. After we brawl our way through hordes of robotic foes, we come to the central control room and have our rematch with Zio. With the Psycho-Wand, we can remove his barrier and face him on even terms... but that doesn't make him an easy target. He can still unleash some nasty attacks like Corrosion (hits the entire party) and he'll fire Black Waves at you; they won't drop you instantly now that you've weakened his powers, but it's still a pretty nasty and powerful single-target attack.
Zio takes a tremendous beating, but eventually falls before the party's combined might. Unfortunately, as Demi is the only one who knows how Motavia's systems operate, she has to stay behind in order to shut the system down and undo all the damage Zio has caused. Gryz also returns to Tonoe in order to watch over his sister, having satisfied his desire for revenge, meaning we're down to just three.
That soon changes, though, as Demi opens a nearby space port, allowing us to take off for Zelan and meet up with Wren, the supervisor of all of Algo's control systems.
Spoony: And no, he's not the same Wren from Phantasy Star III, even though they do look very similar. This is compounded by the fact that both games take place in roughly the same time period (in the US version at least*) and the fact that the two characters have subtly different names in the Japanese version - PS3's Wren is "Shiren" and PS4's is "Forren."
*There is an interesting disparity between the Japanese and US versions of Phantasy Star. In the Japanese version of 3, the war between the Orakians and Layans was said to have ended a thousand years before the start of the game and two thousand years after Alisa III escaped from Parma before its explosion. However, the US version inexplicably drops the latter element, instead saying that both events occurred at roughly the same time 1000 years prior. I'm not exactly sure why they made that change, but either way you cut it, this can't possibly be the same Wren.
At any rate, he states that the reason for the system-wide malfunctions in Algo lies within another control satellite called Kuran, which he has lost contact with in recent days. So he joins the team and we set out for Kuran to investigate.
If Demi was a tank, Wren is a veritable war platform, possessing far and away the highest HP and Defense of any character. His attacks are largely similar to Demi's at first, though he does also get some powerful ones of his own, including the Burst Rocket (which rains missiles on all enemies) and a powerful laser beam called the Positron Bolt. He also comes in handy for quickly mopping up normal enemies once you get his "Pulse Vulcan" weapon a bit later on, which hits all enemies on the field at once.
On the way to Kuran, the ship suddenly encounters engine troubles, and as the group goes to investigate they find some creepy wizard dude mucking around back there. He's quickly dispatched, but not before he inflicts enough damage to force us to crash-land on Dezolis, taking out a holy temple in the process. Ouch.
Of course they're none too happy about that, but one of their ranks, Raja, agrees to overlook it as long as you allow him to join you in order to investigate the Garuberk Tower, which he claims is the source of the ceaseless blizzard plaguing the planet.
Despite his goofy demeanor, Raja is arguably the best character in the entire game. Certainly the best healer at least, as even his basic Res tech can restore over 70 HP (more than double what most characters get). He also has a large TP pool, a skill that can restore TP, one that heals the entire party (even androids!) and a very powerful holy-element attack called Saint Fire that is quite deadly to the forces of darkness (which we'll be seeing a lot of for the remainder of the game). He is relatively weak physically, though, so keep him in the back of the line to minimize the damage he takes.
We follow a lead up north to the town of Tyler, named after a character who made a brief appearance in Phantasy Star II. Examining his grave, we also find that he left his spaceship behind, and that it's still in serviceable shape after a thousand years. They build 'em tough in Algo, what can I say.
That enables us to finally make our way to Kuran, where we find out exactly who is behind all of these recent technological disturbances. It turns out to be none other than our old buddy Dark Force, who has melded himself into the satellite's control systems and is using it to make everything go haywire. Nice.
Being integrated into the machinery, he throws a lot of missiles, electricity and other nasty crap at you. But he's still a being of evil, so he takes quite a bit of damage from holy-element attacks like Chaz's Githu and Raja's Saint Fire. As well as Rune's Efess attack if you have it, which can combine with Chaz's Cross Cut to create the Grand Cross attack and inflict some massive damage.
Dark Force soon goes down and the satellite gets reset; however, the blizzard on Dezolis does not subside, implying that Raja was right and that the Garuberk Tower is somehow responsible. Returning to Dezolis to investigate (and acquiring the Ice Digger in the process), we find that things are worse than originally thought. An entire town has been killed off and zombified, and another nearby town's populace is slowly dying from symptoms similar to Alys', only being kept alive with the aid of the Espers.
Spoony: Which leads to another interesting thing about Phantasy Star. Magic was apparently common in the Algo system at some point (as evidenced by all the characters having a "magic" command in the original game), but after Mother Brain's appearance it faded and got replaced with... something else. Note that in the second and third games it's always referred to as "techniques" rather than "magic". Psionic powers, perhaps? Although it's definitely not psychic power in the usual sense, as it doesn't seem to encompass things like telekinesis or mind-reading. Regardless, "magic" seems to have all but faded by the time PS4 rolls around, with its only practitioners being the Espers on Dezolis - a rather ironic name choice given that the word "Esper" implies psychic ability (ESP) rather than magical. This may just be something that got lost in the translation, but it was always interesting to me at least.
Around this point, you may also come across another optional area where you can encounter Myau from Phantasy Star 1, who even gives you his signature weapon from that game. This is entirely optional, but again, it's a nice little bonus for fans of the series.
The espers make mention of Kyra, a headstrong young Esper who set off for the tower on her own, and Raja soon falls ill, conveniently giving us an open party slot for her arrival. Ah arbitrary party limits.
We follow the path to the tower and soon find Kyra being attacked by demonic trees. Which you can try to fight if you want, but no matter how many times you kill them (and whether you defeat them all at once or not), they will just endlessly regenerate. So despite the boss theme implying otherwise, the correct answer to this problem is just to run away.
Kyra thanks you for saving her and suggests you seek the aid of Lutz at the Esper Mansion. Another familiar-sounding name to those who have played the previous games, as that was the moniker Noah used in Phantasy Star II.
Spoony: And another disparity between the translations, as Noah was always called "Lutz" in the Japanese versions. Although I suppose you could argue it's more of a title than a proper name in the US version.
Once there, we learn that this where Rune hails from (which we already guessed since he refers to his abilities as "magic" earlier on) and that the Espers are the self-proclaimed guardians of Algo. More surprisingly, though, we learn that Rune is none other than Lutz himself! ...Sort of. Lutz's memories are all stored in the inner sanctum in a telepathy ball, and each generation a successor is chosen to inherit them.
Spoony: It's a pretty cool twist for his character, as well as a nice subversion of the usual character archetypes that come with the whole "universal protector" territory. Rune was never shown to be a reluctant hero, and is in fact more than a little aloof and arrogant; he always knew he was the best candidate for the job and isn't afraid to flaunt his position (though he never goes too far with it). Not to mention that Chaz and Kyra's disappointment during this scene is honestly pretty funny.
Anyway, we discover that the trees can be destroyed with the light of the Eclipse Torch (another throwback), so we head to the nearby Gumbious Temple to retrieve it. We arrive just a hair too lat once again, though, as three cloaked goons arrive to steal it, telling Rune to come to Lashiec's air castle if they want it back. As in, the very same flying castle that served as the penultimate dungeon of the original Phantasy Star. And somehow survived the planet's destruction.
As far-fetched as that is, though, I really love this dungeon. They even got a pretty boss remix of the original game's dungeon theme for it, which was a nice touch. And while I generally don't like game franchises recycling dead bosses just so you end up fighting them again and padding out the game, here it does actually serve a purpose to the story, adding to the feeling that there is once again something very wrong in Algo.
Anyhow, we fight through Laschiec/Lassic's goonies (who are pretty easy once you figure out their gimmick - don't use multi-target attacks or they'll ream you) and head into his basement, where we fight the big guy himself once again. Thankfully he's more of a threat here than he was in the first game, as he has quite a bit of powerful magic to throw your way, including some nasty status effect attacks. He also buffers himself once his HP starts to get low which greatly increases his damage output, though thankfully the Psycho-Wand retains its usefulness against dark magic and can nullify that to prevent him from totally stomping you.
He will eventually fall before your combined might, however, allowing you to return to Dezolis, burn up the trees with the torch, and enter
One creepy flesh-maze later, we encounter Dark Force once again, now in the form of a colossal lightning-spewing hellcrab. He eventually goes down (in fact he's pretty easy compared to Lashiec) and the blizzard hanging over Dezolis finally ends. Returning to Gumbious temple, we get pointed to an island temple back on Motavia and told in passing about the "Profound Darkness", the true threat to Algo and by extension the universe as a whole.
Returning to Algo, we get the Hydrofoil and visit the island temple, meeting a character called "Seth" on the way. A guy who suspiciously uses a lot of dark-element attacks like Corrosion, and sure enough, reveals himself to be yet another incarnation of Dark Force as soon as we get the Aero Prism from the temple.
Spoony: I think this also serves as another testament to Dark Force's villainy. Rather than just being another cartoonishly powerful and evil guy, he is quite devious and under-handed, preferring to stick to the shadows much of the time and manipulate others into doing his dirty work for him. This was especially evident in Phantasy Star III, where he manipulated both sides of the war aboard Alisa III to his own benefit. His appearance in Phantasy Star II also suggests he had a role in manipulating the Earthmen in their campaign to destroy Algo as well.
His third form is also probably his most dangerous, being a gigantic beastie with a blade-arm that hits surprisingly hard. You're also at a slight disadvantage owing to having only four people this time around, so this is going to be a tricky one.
At any rate, though, with the prism in hand, we are able to fly into space and reveal the previously unseen fourth planet in the Algo system, Rykros. There we are greeted by Le Roof, a guardian spirit who tells them to seek out the five rings that repel the power of darkness. Which are headgear for some reason. Anyway, they're located in two nearby dungeons, each guarded by a relatively simple boss (immune to holy-element attacks, but surprisingly vulnerable to lightning).
After we do that and return, we finally get some exposition as to what's really going on in Algo. Ages ago there were two warring gods - the Great Light and the Profound Darkness - with the former eventually defeating the latter and sealing it away. Algo was that seal, its populace was tasked with upholding it, and Dark Force is an agent of the Profound Darkness, arising once every 1000 years in the Darkness' name. With Parma's destruction in Phantasy Star II, part of the seal was destroyed, which is why things have recently begun to unravel (and why Dark Force has appeared to us three times now).
Spoony: This is also a source disparity between the versions. In the Japanese release, the Great Light and Profound Darkness were not "gods" per se, but rather a race of people who went to war with one another. The losers in that battle fell into unceasing hatred and eventually gave way to the entity we know as the Profound Darkness. Again, it's not a huge difference in the grand scheme of things, but it is interesting.
Upon hearing this, Chaz becomes pretty upset; after all, if the Great Light is so wonderful, then why are they just left to carry out its will while it's off somewhere else? And if they choose to serve its will without question, how are they any better than Zio?
Rune has an answer for that question, though, taking Chaz back to a hidden chamber in the Esper Mansion. Inside he finds the holy blade "Elsydeon", which houses the souls of Algo's previous saviors - Alis' party, Rolf's team, and even Alys herself, who is shown alongside Alis and Nei (hinting at some sort of link between them, though what it may mean is ultimately left ambiguous). A pretty cool way to tie the whole series together, as well as convince Chaz that he's not fighting for the Great Light, but for all the people of Algo.
The Profound Darkness then makes its move, emerging from a rift on Motavia. The party returns to fight it off, encountering all of their old comrades along the way. Unfortunately, as there are only five rings, you can only pick one character to come with you into the final dungeon. Which, in turn, is something of a "difficulty" select for the final battle. Raja is definitely the easiest owing to his powerful healing skills, while Gryz (or nobody at all) is the toughest.
The Profound Darkness is your typical end-game boss, with three different forms and nastier attacks in each one (culminating in it casting nasty attacks like Megid and nullifying all of your buffers, which is a pretty big liability in this fight!). Still, as your entire team should be pretty heavily decked out by now (and you can actually purchase Star Mists and Moon Dews back on Dezolis, unlike the previous games), you should eventually win out and free Algo of its tyranny. Roll credits.
Spoony: That wraps up Phantasy Star IV, and like I said, it's a brilliant game. It effectively pays tribute to its predecessors while also introducing numerous improvements to its gameplay and providing a satisfying and definitive conclusion to its story. The game also gets props, in my book at least, because it never once tries to overstep its bounds. There's no cheap pandering or shoehorning in philosophical or religious themes in a desperate attempt to sound smarter than it is; instead, it just wants to wrap up its story arc and show the player a good time along the way, and it does exactly that - nothing more, nothing less. Proof that knowing when to stop is just as important an element to a franchise as making sure it's playable, marketable and has lasting appeal beyond a single playthrough.
I would just wrap things up right there, but since this franchise's detractors can't seem to mention it without bringing up some arbitrary and unfair comparison to its "competition" on the Super Nintendo (whilst completely ignoring that three of its games predate the Super Nintendo's release and that the fourth game predates all the "good" SNES RPGs by at least a year), I feel I should address that as well. While the Sega Genesis may have been geared more the "hardcore" crowd with its emphasis on fast-paced action titles competitive two-player games (fighters and sports titles in particular) and difficult twitch-action titles, it definitely proved that it could hold its own in the RPG department as well with games like Phantasy Star, Lunar and Shining Force. They couldn't overtake the immortal SNES trifecta of Super Mario RPG, Chrono Trigger and Earthbound, of course, but they put in a strong effort nevertheless, and the fact that they could create even one game still worthy of hanging with the finest of the genre twenty years after the fact is commendable in itself. Not to mention that at the end of the day, gaming really isn't about "which console is better" or even "which game is better", it's about being entertained - playing fun games, having a good time, and sharing that experience with others. Nintendo and Sega both did just that, pushing their respective platforms' technologies to their limits in order to make sure that their fans, regardless of their favorite genres, got as much value for their dollar as possible, and as far as I'm concerned, that makes them both winners. If anyone says that's wrong... well then, they probably need to step back and reconsider why they started gaming in the first place. Because I somehow doubt the first thought they had when they picked up a video game controller for the first time was that they wanted to spend the next 30+ years of their life desperately trying to rationalize their purchase by having mouth-frothing meltdowns over complete strangers enjoying games they've never even played, let alone given a real chance (and now never will because this is their personal Vietnam and they already picked their side GOD DAMN IT).