Huxian, the Immortal

First strike, lifelink
At the beginning of your end step, each player
creates a 1/2 white Fox creature token with
first strike and lifelink.
Whenever you gain life, you may exile target
creature or enchantment, then return it to the
battlefield under its owner's control. If that card
entering the battlefield would cause you to gain
life, you gain twice as much life instead and that
life gain does not cause this ability to trigger.