The Box of False Bravado

At the beginning of your upkeep, flip a coin.
On a tails, add a doomsday counter to this card. You may give target creature unblockable and ward {1} until the end of turn.

Once this gains three doomsday counters, you and all creatures you control take 5 damage. Destroy this card.

Ingenuity and daring don't always pay off.