Nintendo x Atlus...a Bowser RPG Dungeon Crawler.
You play as Bowser and have a party consisting of 108 classic Mario enemies, including the Koopalings, and go through randomized dungeons. You can take your entire party with you into each Dungeon, Bowser + all 108 as you collect them over the game, but there's a major twist---Bowser is basically the most powerful party member, and the one who determines a Game Over, with the other party members very limited with one or two moves and paltry HP. Basically each Dungeon requires you to smartly conserve your best party members for the major fights and carefully pick and choose when to use each member. Kind of SMT inspired I'm thinking, but with a visual flair bringing to mind Persona Q.