Red is the scenario protagonist, so he's not going anywhere, but I haven't talked about him much so here we go. He's one of the more versatile humans in the game, decent with swords and martial arts. But since he has talent for three of the four DSC moves, I'm training him as a martial artist. His gunmagic skill is 3.
Transforming into Alkaiser, as I said before, means he doesn't level up after the fight is over, but gets a substantial boost to his HP and stats and can learn his unique moves. He can't change if any human, mystic, or monster can see him do it -- if they're in the party, they have to be blind, asleep, or unconscious.
Fuse is easily recruitable in other scenarios, since he joins whoever completes the quest for the Shield Card (even Emelia, I think, even though he hates her). He's the perverted, hot-blooded jackass leader of the IRPO division that keeps coming up in-game, nicknamed "Crazy Fuse". He's a solid character, learning only a few fewer sword techniques than Gen and only a couple fewer martial arts techniques than Liza -- but only two DSC techs. His gunmagic skill is 2, and his stats are geared towards strength, will, and vitality. He's a swordsman, no doubt about it.
Yes, Fuse was supposed to be one of the scenario protagonists. He may have been dropped because they already have a scenario guy who doesn't break the "rules" somehow in Lute. Blue can learn opposing magic schools, Asellus can switch her species, Emelia can trade talent trees, Red can transform into a sentai superhero, T260 is a robit and Riki is a monster. I guess they didn't need two plain ol' regular humans, and Fuse's quest had more content planned so they axed it to save time and money.
Rabbit is a type 2 mec. He's good against other mecs, especially if they have missile launchers he can jam with his ECM system.
Cotton is a monster. I really don't need to describe monsters again, do I?
Doll is the voice of reason for the freakshow that is the rest of IRPO, since she's actually got a little common sense in her mostly-shaven head. Her cool demeanor has earned her the nickname "Icy Doll". She's not very good with swords or fists, learning very basic techniques almost exclusively, but her gunmagic skill is 6. Her stat growth is geared toward intelligence and charm, making her an ideal gunner/caster.
Silence is a mystic, so he has the usual talent for casting and soul-sucking you'd expect. His outfit that sprouts moth wings when he casts a spell earned him the name "Narcissistic Cosplay Jerk" from Fuse.