Use Gig Edicts on Townspeople
That option we've seen in every town but never been able to actually use to any effect becomes unlocked after the first cycle. This has four main effects - Fighting people (for items and cash), Stealing from them (getting rare items if you succeed, having to pay a hefty cash penalty if you fail), Combining (which gives a significant boost to one of your stats) and Kidnapping (recruiting Manikins with decent starting levels and higher stats than normally available). Of course, you can also kick people around and treat them like dirt if you just feel like being a dick.
An alternate story mode where Revya decides to use Gig's powers to well, go on a killing spree. You recruit several enemy characters from the main storyline, as well as kill off most of your former comrades. Fun if you feel like being a bastard, I suppose.
For finishing the game once you unlock the Gideon class, which is pretty much the ultimate melee unit. Not only do they have high stats all around and Flying movement type, but all of their attacks hit multiple targets - their front row attack hits an entire file, and their middle and back rows hit every enemy in a room. Their only true weakness is that they cost a ton of cash to create and deploy (but if you're halfway decent at Soul Nomad, you should never be short on cash anyway, right?).
(Spoilertastic, so don't watch these videos if you don't want to ruin the scenes for yourself)
Lujei - If you have the "Reveal Path 1" Edict (buy it in the shop for 5,000,000 GP), you'll get an alternate dialog option during the Raide Oceanside event just after the attack on Yesterwind. Picking that will play an extra scene between Endorph and Lujei. Once you defeat her, she becomes a playable character.
Lujei is a boss character from the game "GrimGrimoire", which NIS published in North America. It also pretty much confirms that Walnut and Endorph are one and the same.
Asagi - A bit of a joke character in Nippon Ichi's games. She was intended to star in a game called "Makai Wars", but since that game got cancelled, she's made cameos in many of their other games, trying to defeat the hero and take their place. Soul Nomad is no exception.
If you defeat Feinne during your first encounter (without Gig's help), you'll view an alternate scene where Asagi challenges you to a battle. If you defeat her, you get an alternate ending and she becomes a playable character. Due to a bug in the game, you can also recruit multiple copies of Asagi and even potentially make entire squads of her. Pretty funny.
Median - After viewing the flashback event in Corsius Manor, if you have the "Reveal Path 2" Gig Edict*, you'll get an alternate dialog option that allows you to fight Median. There are two alternate endings depending on whether you win or lose the battle. Defeating him also enables him as a playable character.
*This only appears in the shop after you defeat and recruit Lujei. It will also run you about 5,000,000 GP.
There are several extra rooms to unlock beyond what you get in the main game.
Happy Hall - Complete the normal game once. GP earned by this room increases by 50%.
Demon Bed - Complete the Demon Path once. Boosts all stats by 50%, but all stats drop 10% each turn.
Lightsinger - Clear 20 floors in a 2000 GP room inspection. Boosts the stats of all allies' rooms by 10%, but lowers the stats of your own room by 30%.
Darksinger - Clear 30 floors in a 6000 GP room inspection. Lowers the stats of all enemy rooms by 10%, but also lowers the stats of your own room by 30%.
Sarcophagus - Clear 60 floors in a 20,000 GP room inspection. All squads adjacent to this room will take damage equivalent to 10% of the squad leader's HP each turn.
Talent Show - Clear 80 floors in a 40,000 GP room inspection. This room is invincible for 3 turns, but dies instantly on the fourth turn.
Fist Dojo - Clear 100 floors in a 60,000 GP room inspection. Attacks from units in this room can cause instant death, but award no experience.
Kitty Pen - Defeat a Shop God. Boosts the stats of all units in the room by 10% for each completed game cycle.
As stated in Part 1 of this series, you earn affinity points through dialog choices during story scenes, as well as gaining a point each time Revya does a team attack with that character (with the exception of Gig, obviously). Whoever has the most points at the end of the game gets an extra scene. In the event of a tie between two characters, the game defaults to Danette's ending.
These endings also seem to all be concurrent - that is, they all canonically take place. I listed them in the order they seem to chronologically take place in.
Levin Ending "Two Wandering World Eaters" (M / F)
Tricia Ending "The Righteous Path"
Layna Ending "Caretaker of Drazil"
Juno Ending M "Juno's Proposal" / Juno Ending F "Penn's Proposal"
Gig Ending "A new adventure" (M / F)
Danette Ending "Looking toward the Future" (M / F)
Grunzford Ending "Indefinite Journey" (M / F)
Vitali Ending "A Dream Realized"
Odie Ending "I Still Get No Respect"
Endorph Ending "Respite for the Restless"
So Revya travels with Levin for a while, eventually parting ways to wander the world and meet with old friends. Then he/she returns to the Hidden Village to find Danette and Gig waiting for them, then they set out on another journey before too long. Makes sense to me, at least.
You're probably wondering "Wait, weren't Levin and Euphoria both killed by Raksha?", and you'd be right. But they were both part of a World Eater, and given that we've seen World Eaters and demigods cheat death several times already, it's not too much of a stretch to think they could come back as well.
I've also heard that if you have the most points with Levin or Endorph before the event with Raksha goes down, the scene changes slightly so that Levin (if Levin has the most points) or Euphoria (ditto Endorph) survives. I haven't witnessed this firsthand, though.
We'll do the Demon path another time. For now, I have some other long-neglected projects I need to work on. We'll have more Let's Plays coming soon though (plus I still need to wrap up the last two quests in SaGa Frontier), so stay tuned!
Special thanks to The Cock Crew, OmegaPrismZ and HaseoXLeon for the embedded videos on this page.