Quintessa, Prime of Life

Deathtouch, lifelink.
{1}{p/w}{p/u}{p/b}, {t}: Sacrifice a land: Target
land becomes an artifact in addition to its
other types. Gain control of it at the beginning
of the next end step.
If you control at least three or more permanents
you don't own, exile Quintessa, Prime of Life,
the return her to the battlefield transformed
under her owner's control.
Activate this ability only during your turn.