Apocalypse, The Burning Hate

Apocalypse cannot be cast unless a permanent
has left the battlefield this turn.
{b/r}{b/r}{b/r}: place a burn counter on a permanent.
At the beginning of your upkeep, put a burn
counter on any permanent with a burn counter
on it, then destroy all permanents with X or
more burn counters, where X is their converted
mana cost.