Fifty Fifty

Fifty Fifty enters the battlefield with two decision
counters on it.
At the beginning of your upkeep flip a coin. If you win,
put a decision counter on Fifty Fifty. If you lose,
sacrifice Fifty Fifty.
{t}: Remove a decision counter from Fifty Fifty. Flip
a coin. If you win, counter target spell.
When Fifty Fifty would leave the battlefield, flip a coin.
If you win, it doesn't.