Mask of Winters

Hexproof, Provoke, Wither
Whenever an opponent casts a spell, you gain life
equal its converted mana cost.
Whenever you cast a spell, you may return a
creature with that spell's converted mana cost or
less from your graveyard to the battlefield.
Creatures your opponents control come into play tapped.
Creatures your opponents control lose haste and
cannot have haste.