Ooh good question, what would you make?
CREATE A NEW CHESS PIECE!
Marquee, a piece that moves like a king but captures any piece in it's range automatically without taking your turn.
Catapult, a piece that moves like a king but captures by launching a stone forward 1, 2, or 3 squares. Does not move when capturing. Stone can go over pieces.
Trojan Horse, a regular knight that spawns a special pawn when captured. The pawn can be promoted back to a Trojan horse by reaching the opponent's back file or capturing a knight with the pawn.
Defender, a pawn that has a shield which can tank one hit. Once the shield is down, it turns into a regular pawn.
Archbishop, a bishop that can move only on squares not controlled by bishops. Turns into a queen when it captures a bishop.
Bandit, a piece that moves like a king, but has double the range. It can "chain" onto multiple pieces when captured. If it captures a pawn that is next to another pawn, both pawns are captured and the bandit lands on the square that the second pawn was.
The cannon, it can blow up an empty square making it unusable but can only be fired once then becomes captured. It fires like a queen.
Can absorb a piece in a 2x2 square without moving. Moves in one diagonal square each move. Every absorption will turn the piece into a shadowed version of itself.
The princess. Moves like the king. Can change places with any friendly adjacent minor piece to avoid capture. Friendly rooks can jump over her to capture in defense of the princess.
So the rules are simple, create a piece that does not exist in variants or regular chess. Please keep all pieces family friendly and non political. Have fun!