Spirit of the Six Samurai

[ Warrior / Effect / Union ] Once per turn, you can either: Target 1 face-up "Six Samurai" monster you control; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. While equipped by this effect, the equipped monster gains 500 ATK and DEF. If the equipped monster destroys an opponent's monster by battle: Draw 1 card. (A monster can only be equipped with 1 Union Monster at a time. If the equipped monster would be destroyed, destroy this card instead.) ATK/ 500 DEF/ 500