How to mate with two bishops?

Its super easy ???

Same principle as mating with a tower - you put the king in zugzwang and every time it moves, you limit their space more, until there is no more space and its mate.

Both tower and bishops need help from the own king, while a queen can do it alone.

Without any optimization, it looks like this:

Again, I havent optimized. Its definitely possible to do it faster; IIRC it takes at most 16 moves to checkmate with a pair of bishops.

Maybe as a pointer: unlike a rook a pair of bishops can keep the king in a cage, without the help from their king, like this:

Unlike a queen however which can do this over and over, bishops cannot progress on their own.

So thats why you have to use the king as well, so you can support the bishops while they drive the king closer and closer to a corner.