Crystal Wing Synchro Dragon (OP13-EN008) - OTS Tournament Pack 13 Unlimited

1 Tuner + 1+ non-Tuner Synchro Monsters
Once per turn, when another monster's effect is activated (Quick Effect): You can negate the activation, and if you do, destroy that monster, and if you do that, this card gains ATK equal to the destroyed monster's original ATK until the end of this turn. If this card battles an opponent's Level 5 or higher monster, during damage calculation: This card gains ATK equal to the current ATK of the opponent's monster it is battling during that damage calculation only.