Hallend, Ancient Sage

Shroud, Farsight (At the beginning of your turn, you may look at the top three cards of each opponent's library, then you may put them either at the top or bottom of their library, and in any order you choose.)

At the beginning of your turn, one of your creatures gets +X/+X until the end of the turn where X is the total of all tapped creatures on the battlefield.

Any time an opponent casts a spell, they must tap one creature.