During damage calculation, if a "Warrior" Synchro Monster you control battles an opponent's monster (Quick Effect): You can send this card from your hand to the GY; your battling monster's ATK becomes double its current ATK during that damage calculation only. You can banish this card from your GY, then target 1 "Synchron" monster in your GY; add it to your hand. You can only use each effect of "Rush Warrior" once per turn.