Berserker's Grudge

When a creature you control is exiled or sent to
the graveyard by a spell or ability an opponent
controls, you may discard this card. Berserker's
Grudge can be cast only if it was sent to the
graveyard this way.
Flashback {2}{r}
Until end of turn, if a source you control would
deal damage to a permanent or player, it deals
double that damage to that permanent or player
instead.