Chained Elemental

Defender, Trample
Unbound {2}{u}{r} (X: Put this creature onto the battlefield from your hand. Unbound only any time you could cast a sorcery.)
{t}, return Chained Elemental to your hand: Add{2}{u}{r} to your mana pool.
When Chained Elemental enters the battlefield, if its unbound cost was paid, it loses defender.
Its rage cannot be contained for long.