Dogurad, the Stonetrooper

2+ monsters, including a Rock monster
If this card is Special Summoned: You can target 1 Rock monster in your GY; this card gains ATK equal to that monster's ATK. During your opponent's Main Phase (Quick Effect): You can target 1 other monster on the field with ATK less than or equal to this card; this card loses ATK exactly equal to that monster's ATK, and if it does, destroy that monster. You can only use each effect of "Dogurad, the Stonetrooper" once per turn.