Screaming Bell Of Doom

Whenever a Rat you control dies, put a doom counter on Screaming Bell of Doom.
{b}, {t}: Each opponent mills cards equal
to the number of doom counters on Screaming
Bell of Doom.

Threshold — At the beginning of your end step, if there are 13 or more doom counters on Screaming Bell of Doom, sacrifice it. Each opponent loses life equal to the number of cards in their graveyard.