Soul of the Calling

Equipped creature gets +1/+0 and has haste.
Whenever you or equipped creature deals damage to an opponent, you may pay {x}{r}. If you do, put a creature from your hand with converted mana cost equal to X onto the battlefield and equip Soul of the Calling to it.
Equip {r} ({r}: Attach to target creature you control. Equip only as a sorcery.)