Design for heavenly realm studio chess game version I (Not my own game)

in the affairs of an army, there is nothing more intimate than spies.
None should be more liberally rewarded, and no other matters should be more confidential. Spies cannot be usefully employed without a certain intuitive sagacity.
They cannot be properly managed without benevolence and straightforwardness.
Without subtle ingenuity of mind, one cannot make certain of the truth of their reports.

                              ------The Art of War(孙子兵法)

Players can collect a variety of characters. All characters are divided into four categories: Seer, Striker, Support, and Spy.

Before entering the game match, players will select one character from each of the four categories. At the start of the game, these characters will be assigned to pieces on the board. The Seer, Support, and Striker will be assigned to one to three of the player’s own pieces, while the Spy will be assigned to one of the opponent's non-king pieces.

The Spy is visible only to the player who assigned it, while other characters are visible to both players by default unless specified otherwise by special abilities or skills.

You win if the opponent's King is defeated and their Spy is also defeated, or if your own King is defeated but your Spy survives.

You lose if your own King is defeated and your Spy is also defeated, or if the opponent's King is defeated but their Spy survives.

Seer-type characters can help narrow down the range of the Spy when certain conditions are met, such as capturing an opponent's piece or occupying a specific position on the board.

While Striker-type characters are alive, they can attempt to capture allied pieces. If the captured piece is a Spy, the Striker will successfully capture it. If it is not a Spy, the move is canceled, and the turn immediately switches to the opponent.

If the Striker is defeated, any allied piece can attempt to capture other allied pieces, and the capture will succeed regardless of whether the piece is a Spy or not.

Support-type characters are typically used to help an allied Spy remain hidden. They can, for example, disrupt the opponent's information or even transfer the identity of the allied Spy to another piece once.

Spies can possess various abilities. Some focus on survival, such as blocking a Striker's attack once. Others offer high-risk, high-reward mechanics, such as causing the opponent's corresponding piece to disappear whenever the Spy captures a piece.