Sea supremacy

A fun battle chess game.The rules are simple. Both sides only need to manipulate their own pieces and eat the other pieces to win.

1. At the beginning of the game, a player randomly plays a turn and decides the color of the two pieces.
2. Each turn, the player controls only one pawn to move a pawn.
3. Pawn size order: sea urchin> blue whale> killer whale> shark> dolphin> swordfish> octopus> sea turtle> sea urchin.
Both the same pieces are eliminated.
When the small chess attacks the big chess, the small chess disappears.
4. Both sides automatically draw if they do not eat each other's pieces for 20 consecutive moves.
5. In the end, if there is only one chess piece left on both sides, the chess piece wins, and the two chess pieces are the same.