Chess... but what if it was an open world game? Thread

Still a WIP! I want to add a lot of different things around the map and probably even randomly generate it!

As you can see I also added 3 more pieces; The Mouse, the Soldier and the Emperor. The mouse is a mix between the Knight and the Rook, The Soldier is a mix between the Bishop and the Knight and the Emperor can literally go anywhere in a 8x8 radius except in front of him.

Also took some creative licenses to modify the Pawns (And probably any other piece that doesn't make sense), they can go backwards and can eat from all directions now!
I accept suggestions on new piece ideas!

I've pondered (and given up!) on the idea of an open world chess game in the past. Chess is a very finely balanced game, it can't be easy to turn it into open world, but if you can find a way to make this work it sounds like a lot of fun.

Piece ideas: Have you seen previous pieces that have existed in the past or exist in variants? Think I heard of a piece that can move 2 spaces in any direction (think it was called a prince).

With the "bigger board" is it worth allowing knights to make multiple jumps in the same direction? The long range pieces would be stronger given the advantage while a knight may become less useful, I would imagine it needing a boost. Would a pawn have any way to promote? While regular chess has some special case moves (castling, en passant), perhaps you could add a few others to support more freedom. Something tells me there would need to be a lot more pieces to fill the bigger world. Perhaps some currency system to purchase more pieces?