If I go into battle with midianite's slave, capture him to LoB, and add my joseph to battle, could joseph use hidden treasures? My guess is no, based off the begins a battle section in the REG, but i just want to check. however, I do remember that you can use someone like AotW to exchange for a prophet, and they can then use hidden treasures. has that changed from the last REG update?
Midianite's slave: You may capture this character to to opponent's LoB to add your son of Jacob to battle and each player may draw two.
Joseph's ability doesn't matter, but he is a son of jacob and a green prophet.
Hidden treasures: Once per turn, if your lone green brigade prophet begins a battle, you may do a thing.
Begins a battle