Collosus, Demon King

In addition to this creatures cost, sacrifice a creature.
When this creature comes into the battlefield, destroy all creatures with strength 2 or less.
Indestructible, Hex-proof,
When this creature is destroyed, or exiled, sacrifice a creature and play {b}{r} , and then put Collosus back on the top of your deck. When Collosus is in play, all {r} and {b} spells cost {2} less. You can use {b}/{r} spells more than once if you pay an extra {p/b} or {p/r}.