2016-04-08 : 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.

2016-04-08 : 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.

2016-07-13 : For more information on double-faced cards, see the Shadows over Innistrad mechanics article (http://magic.wizards.com/en/articles/archive/feature/shadows-over-innistrad-mechanics).