Everblazing Overbeing

Volatile (Place an X counter on this creature. At the
end of each of your turns, subtract 1 from the counter.
When the counter reaches 0, destroy all creatures on
the battlefield.)
{x}{r}: Everblazing Overbeing deals X damage to
any target. If a creature dealt damage this way
would die this turn, exile it instead. Shuffle Everblazing Overbeing into its owner's library.