Chess solved this problem a long side ago, with odds - a stronger player may remove pawn(s) or piece(s) from their side of the board, to give the weaker player a winning chance (and to give themself a challenge). And it’s completely transparent (well, you do see the initial board state, right?).

With some good design, plenty multiplayer games could implement the same idea - giving the more skilled player a bigger cooldown, less HP, or perhaps even restricting a few combos deemed too powerful.