Txun, Master of Luck

Pay 1 life: Flip a coin. If you win the flip, put a +1/+1 counter on Txun, Master of luck. If you lose the flip, put a -1/-1 counter on Txun, Master of Luck, and you gain 1 life.
Whenever a counter is placed on a creature you control, you may deal X damage to target creature where X is the number of counters on Txun, Master of Luck. If you do, you lose 2 life
Luck is where opportunity meets preparation.