Oscuro of Viznagar

Menace, deathtouch, indestructible

You don’t lose the game for having 0 or less life.

If you were to lose life while at 0 or less life, instead amass Birds X, where X is the amount of life you would have lost. (To amass Birds X, put X +1/+1 counters on an Army you control. It’s also an Bird. If you don’t control an Army, create a 0/0 black Bird Army creature token first.)