@Opossum would like a word with you.
Anyways, what Assist Trophies do you guys want to accompany the DLC characters, along with your most wanted?
I made a thread asking this a while back. My picks are:
Joker: Jack Frost
Hero: Golem
Banjo: Mumbo Jumbo
Terry: Nakoruru
Byleth: Hanneman
Sora: Riku
Crash: N. Trance
Arle: Schezo
Jill Valentine: Chris
Axel Stone: Mr. X
Joker: Futaba, she's the only team member (besides Crow) not to be featured in Mementos and that's a crime. Her Persona, Necronomicon, could hover right above a certain character and scan them. A monologue would trigger from Futaba herself and she'll enrich the audience with her amazing nerd knowledge on the fighter she scanned. She would then buff the player who summoned her as she leaves the stage.
Hero: Seeing as that Fighter Pack was heavily focused on DQXI, I'd pick Jade. She'd lock a fighter in a rapid combo involving her spear.
However if I could pick a character from the franchise in general, I'd pick Terry, his Dragon Quest Monsters incarnation in fact. He would summon random iconic Dragon Quest monsters on the stage (Slimes, Golems, Saber, etc...), they would then attack random fighters.
Banjo: I've never played Banjo&Kazooie so I can't really say... uhm. Let's just look at the wiki and pick a random character. Oh, Conga the Ape. He looks like he could beat the living out of people! Conga the Ape it is then.
Terry: Seeing as Geese is already a cameo on the King of Fighters stage, I'll pick another iconic hard-as-balls boss: Rugal Bernstein! He'll use moves like Genocide Cutter, Geese's Reppuuken and Krauser's Kaiser Wave.
Byleth: Gatekeeper all the way, best character in Three Houses hands down. He'll just stand on the stage and do nothing, he's already perfect.
Now as for the Assist Trophies that will come with my most-wanted characters.
Phoenix Wright: Godot is absolutely my favorite character of the entire franchise. Everytime he gets summoned his jazzy theme, The Fragrance of Dark Coffee, will start to play. He'll then proceed to shout "OBJECTION" at random players, and everyone who gets caught in his objection bubble will receive damage and get knocked back very far. Oh yeah, he will also throw cups of coffee at you. Typical Ace Attorney stuff.
Sol Badguy: Justice could serve as both a Boss and an Assist Trophy. She'll execute VERY powerful moves like her iconic Gamma Ray (which is basically just a very big Hyper Beam) and her Instant Kill, X-Laser. Where she grabs a fighter and rapidly flies up, ending the attack with a huge explosion.
Kazuma Kiryu: Majima of course! He'll run through the stage slashing everyone in his way with his knife. If Kiryu is a fighter on the stage, he'll target him specifically while screaming "KIRYUU-CHAAN!". He breakdances occasionally.