Cosmic Devour

At the beginning of each player's end step, that
player returns a permanent they control to their
hand, then discard a card and loose 1 life.
Every time a player looses life, put a number of
life counters on Cosmic Devour equal to the
amount of life gained. If Cosmic Devour would
leave the battlefield under any circumstance, the
player of the current turn gains life equal to the
number of life counters on Cosmic Devour.