Abraham, The lost mage

You may summon this creature from your hand to the battlefield by discarding 3 cards
instead of paying its mana cost
When Abraham, The lost mage enters the battlefield target creature you control gets +X/+X
and gains Double Strike where X is how much
mana you tapped to cast this creature
Annihilator 3 (When this creature attacks, defending players sacrifices 3 permanents)