Birthing Sphere

When Birthing Sphere enters the battlefield,
choose target creature an opponent controls.
Exile that creature until Birthing Sphere
leaves the battlefield.
{t}, {2}: Create a 1/1 creature token that is a copy
of the creature exiled by Birthing Sphere.
{t}, {2}, Sacrifice Birthing Sphere and at
least three token copies of the creature exiled by
Birthing sphere: Gain control of target creature
that was exiled by Birthing Sphere.