Heroes and Allies

Et Tu, Brute?: Though Mark wasn't exactly considered an ally at this point, 81 makes almost a complete heel-face turn when he finds out Mark was seemingly behind Pablo's death, holding onto the hope that maybe he could be trusted. Though as it's revealed later, Mark was framed.
Passive-Aggressive Kombat: Does this with Mark a short time after the latter joins the party, just to make it clear he's still not welcome just yet.
Pint-Sized Powerhouse: Quite strong for his lanky build.
Slasher Smile: Displays one of these near the beginning of Region Tri, and in most subsequent instances where Mark is mentioned; eager to wipe him out.
The Berserker: Slowly develops into one the more the story progresses, eager to just kill whatever he needs to so he can get back home.
The Leader
Token Human: Between the last remaining Elsen, the element of Smoke taken form, and a Purifier, 81 serves as the only human in the main cast.
Tragic Hero: Described as such by the creator.

Zinzolino

Beware the Silly Ones: Similar to Bad Batter, Zinzo's affable personality is used to make his prey let their guard down.
Big Eater
Paste Eater: Though not shown in canon, given his tendency to ask whether (insert object he's never heard of) is food, it's likely Zinzo has consumed inedible objects before, being the oblivious glutton he is.
Third-Person Person: Though not all the time, he has his moments. This goes hand-in-hand with his childspeak.

Ylidomda

Expressive Mask: Her eyes are sometimes shown through her lenses, and they can even turn red if she's angry enough.
Laser-Guided Amnesia: We find out later that she specifically went to Lenny to have her memories erased, particularly ones relating to her time in the war.
Loss of Identity: At the beginning of the story, she's had her memories wiped, not even remembering she's a Purifier until called one.
Trauma Button: Witnessing an explosion makes her recall terrible memories of her past as a soldier.

Mark

Sarah

Pablo

Bakudan

Antagonists

Playing Card Motifs: The four elemental Knights (Smoke, Plastic, Metal, and Meat) are each attributed to a card suit.
- Smoke Knight = Spades.
- Plastic Knight = Diamonds.
- Metal Knight = Clubs.
- Meat Knight = Hearts.

Smoke Knight

Blow You Away: As her name suggests, she's a Smoke/Wind elemental knight.
Siblings in Crime: With Plastic Knight.
The Perfectionist: This is the crux of her personality; Smoke Knight is a perfectionist obsessed with making robots who will be able to create a masterpiece that far exceeds her expectations.

Plastic Knight

Boss Banter: Due to the mechanics of his fight, Plastic is the only boss that does this to any meaningful degree.
Making a Splash: A merman living in a sea of plastic, this knight is a Plastic/Water elemental.
Siblings in Crime: With Smoke Knight.

Metal Knight

Dishing Out Dirt: As the name implies, he's a Metal/Earth elemental.
Don't Call Me "Sir": Says this to 81 when they first meet.
Metalhead: True to his name, at his core, he's just a guy who loves to rock-n-roll.
Theme Naming: See above, all of his competences have something to do with music (Guitar Smash, Reversed Song, Soundtrack of Fury, and Half-Toned Tune, to name a few).

Pure Knight

Bragging Rights Reward: Incredibly beefy and difficult to beat, Pure Knight will still win even if you manage to reduce his HP to zilch. In that rare case, however, beating him doesn't give you anything special other than a few Orbs and healing items that can be looted from regular enemies.
Deadly Upgrade: Pure Knight is actually Ghost Batter, injected with Godhood extract of his own free will in order to become a better Purifier.
Death of Personality: Pure Knight essentially becomes an unfeeling war machine once he ascends to Godhood.
Just Following Orders: Doesn't kill for fun in the same way a Blood Knight would due to having the full spectrum of his emotions under lock and key; simply removes obstacles that get in the way of what he's commanded to do without a second thought.
Light Is Not Good: Following the general theme that OFF creates, a Purifier who makes everything white and clean does not equate to them doing what is right.
The Heavy: Shares the spot with Lenny. While U-Gore can be interpreted as this story's "antagonist," these two notably cause the most trouble for the protagonists throughout the course of the story.

Lenny

All Your Powers Combined: Derivative. Using the competences "Full Deck" and "Joker's Poker," he can use any move he's hit with against the enemy party. He'll start absorbing competences once he uses Full Deck, and after a while will have to empty it in order to gain new moves.
Dirty Coward: You don't even get the chance to whittle his HP down to 0, he'll run away before being killed no matter what, the chicken he is.
Faux Affably Evil
The Heavy: Shares the spot with Pure Knight. While U-Gore can be interpreted as this story's "antagonist," these two notably cause the most trouble for the protagonists throughout the course of the story.

U-Gore