Sovereign Chess

Suppose a white knight is pinned to the white king by a green bishop controlled by Black. Could White legally move the knight to capture the black piece on the green square? At the end of the turn Black would no longer control the green bishop, so the white king would not be in check.

My guess is that you will want to say no. One can't castle through a square attacked by the opponent, and that suggests that it's not just avoiding check at the end of a turn that's required, but through the whole turn. Allowing the knight to move wouldn't fit this pattern very well.

This move is allowed, as long as the king is out of check by the end of the turn.

Presumably it is also possible for, say, a pinned rook to move to a purple square if the other purple square blocks the check as a result.

This is an interesting feature of Sovereign Chess. Some pins that would be absolute in standard chess can actually be broken.