The Cost of Vengeance

At the beginning of each players upkeep, that
player flips a coin and gains control
of The Cost of Vengeance.
Heads: You immediately proceed to your end
step unless you discard down to one card.
Tails: Draw a card, put two +1/+1 counters on
target creature, and add three mana of any colour
to your mana pool.
Whenever The Cost of Vengeance leaves the battlefield, exile it. Return The Cost of
Vengeance to the battlefield under your control.