I already have a few bosses:
Mask, (PaintedFish)
Wurboc, (YourLocalWubboc Had to change name because of copyright)
The Spoon Samurai, (...Little obvious right?)
Embro_0018 (Flare the Fire)
I have an idea for an Undertale x Nine Sols games; It's a game placed in the future and there were 6 Factions, One day they all went to war with each other, But one day a meteor hit earth nearly killing every single living being alive. But you as the player can either, Help rebuild, or Kill every last being alive. I'm taking requests for the mini bosses here the the themes of each area. 1: Ruined City, Robots, Japanese Temple, Lava, and Undead.