Pokémon chess.
You pick the Pokémon from tiers for each piece, then play regular chess.
Plays like regular chess, but when a piece takes another, what instead happens is that a regular Pokémon battle ensues between them.
If attacking and succeeds, you take the pieces place like in regular chess, but if you attack and lose, you just remove the attacking piece from play . The defending piece remains in play, but with hp damage.
Game ends when you get checkmated or I guess if your king faints or something idk
And if for some reason it works better with a chess variant, be my guest.
https://en.wikipedia.org/wiki/List_of_chess_variants 