Can Bill do this after both players have activated switches, or does the player controlling Bill have to do it during his/her Switches phase? For Example, Mushashi moves up to Bill and uses Ken no Sen. As the active player, Mushashi makes Bill switch first. Bill doesn't use any switches. Then Mushashi changes all his blocks to successes. Now that Bill can get damage, can Bill use Dead Man's Hand now to discard a Tactic?