I think that KI could do well with a 3D beat em up like MK Shaolin Monks. Start with Jago and Orchid and maybe unlock other characters that can be used. Have them gain special moves, power them up, etc.
You can have ultratech suits, other experiments, etc as the regular cannon fodder and use characters like Fulgore, Riptor, Cinder, Sadira, etc as earlier bosses. Then have the story go from the KI tournament all the way through the Gargos invasion and have Eyedol, Shadow Jago, Omen etc as bosses with Gargos acolytes, mimics and shadow characters as additional cannon fodder.
Obviously more can be done here for variety’s sake, but there could be branching paths, optional side quests leading to other bosses like Mira, Kan Ra, Spinal etc, tag team moves, ultimates, and tons of stuff to unlock.
I could also see a KI JRPG. I don’t think it’s particularly hard to turn any game IP in to a JRPG provided there are a few story / lore elements and I think this game has more than enough.
But yeah, start out with Jago, Orchid and Thunder as they’re traveling to the KI tournament. Have them recruit other characters during the early/mid chapters like TJ Combo, Maya, Tusk, Kim Wu, then later when the story changes from ARIA being the big bad guy to Gargos, you recruit, Sadira, Fulgore, Cinder, Kan Ra, and ARIA.
There could be side story characters like Wulf, Fulgore, Eagle, Aganos, Hisako (who becomes Shin Hisako), Glacius, etc that enter your party and leave once their story conclude, or perhaps some stick around.
Maybe give the player the ability to create two parties after the invasion starts and send them out on different story paths, where they fight battles, advance their plotlines, search for things needed to destroy Gargos, gain levels and tech and what not, and they cross paths again at key points in the story.
Maybe you have a Nightguard faction with one Ultratech character and an Ultratech faction with one Nightguard character, and the teams trade fighters at various times to advance certain sub plots.
The game could be both turn-based and fighting game-based, so certain areas will force you to fight one way or the other. But it could have a lot of the RPG genre ideas, like Instinct Mode could be a sort of Final Fantasy limit break status where they get to do a really cool move that does a lot of damage, but you unlock several instinct mode buffs or attacks throughout the game.
Characters could have certain jobs that reflect their in-game abilities, perhaps only characters with projectiles can use spells, shadow moves could have different elements attached to them, there can be multi-team member moves, characters could learn ultra combos and ultimates, perhaps you can call in assist characters.
There could be a gauge that charges during the match where your team spends points in a pool to do certain actions like Skies of Arcadia, so a leaping slash would cost X amount, shadow leaping slash would cost X+2, Sabrewulf’s ultra would cost X+40 or whatever.
Man, I would freaking write that story just to see that game happen. 