Chibaku Tensei

Enchant creature or planeswalker.
Enchanted creature or planeswalker loses all abilities and becomes a 0/10 colorless golem land creature with "{t}: Add {1} to your mana pool."
Whenever an opponent casts a creature or planeswalker spell, create a copy of Chibaku Tensei and attach it to that permanent.
"Behold! My gift to this world!" -Pain