Aeris, The Flayer

Whenever Aeris, The Flayer or another Warrior
you control deals combat damage to a player you
may pay {2}{r} to put a charge counter on Aeris,
The Flayer.
If Aeris, The Flayer has five or more charge
counters on it, anytime a source you control
would deal damage to a permanent or player,
it deals double that damage to that permanent
or player instead.