Khorvath's Fury

Players can’t take actions in between the time that friends perform their actions and the time that foes perform theirs. If any abilities trigger from friends performing actions, those triggers won’t be put onto the stack until the foes perform their actions and the spell finishes resolving.

If a friend has zero cards in hand, that player discards nothing and draws one card.

The designation of friend or foe is only relevant to the spell that asks you to choose. A player you call your friend doesn’t become your teammate, and the next “friend or foe” spell you cast could name that player your foe.