If you have no cards in hand after Sage of Ancient Lore enters the battlefield, it will be put into your graveyard before its first triggered ability resolves. You'll draw a card, but Sage of Ancient Lore will already be gone.
2016-04-08 • wotc
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 • wotc
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.
2016-04-08 • wotc