To trigger the Werewolf's back face's transform ability, a single player must have cast two or more spells during the previous turn. If multiple players each cast just one spell during the previous turn, the ability won't trigger.
At the beginning of each upkeep, if no spells were cast last turn, transform this creature.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform this creature.
The abilities that transform a Werewolf back and forth look at the entire previous turn, even if the Werewolf with that ability wasn't on the battlefield for some or all of that turn.
