Aeos, whirlwind of death

Flying, haste, double strike, deathtouch
Auras and equipment cost {3} less to cast.
Instead of paying this cards mana cost, you may sacrifice 3 creatures.
if this creature would be exiled, put into a
graveyard, on top of a library, or into your hand, instead return it to the battlefield tapped.
{t}, sacrifice a creature: put a +1/+1 counter on
this creature, any opponent may use this ability.