Pack Ambush

Ambush X (You may exile up to X cards from
your hand. If you do, place them face-down
without revealing. Starting at the next end
step, you may play those cards as if they have
flash.)
Pack Ambush costs {1} less for every card
already exiled under your control.
"The best strategy is to never let your enemy
know they are fighting."-Castor, Freedom Fighter