Mosasaur Fortress

As an additional cost to cast Mosasaur Fortress, sacrifice a permanent.
When Mosasaur enters, destroy up to one target creature an opponent controls.

As long as Mosasaur Fortress is equipped, it has deathtouch and lifelink.

Whenever Mosasaur Fortress deals combat damage
to a player, that player loses half their life total, rounded up.