Yadron, The Unholy

Flying, hexproof
Whenever Yadron, The Unholy attacks, reveal
the top card of your library. You may cast that
card paying life equal to its converted mana cost
rather than pay its mana cost. If you don't, put
that card into your hand and you gain life equal
to its converted mana cost.
"They've betrayed me. So I've betrayed them, then
killed them all."