Asburg, Sower of Depths

Deathtouch, Hexproof
Whenever Asburg, Sower of Depths attacks, you may pay {p/u}{p/u}{p/b}{p/b}. If you do, you may destroy target creature with flying or gain 3 life.
Whenever Asburg, Sower of Depths blocks, he gains indestructible and deathtouch until end of turn.