If you control "Regulus, the Prince of Endymion": Activate 1 of these effects; • Destroy 1 monster your opponent controls that battled this turn. • When a Normal or Quick-Play Spell Card is activated: Negate that effect. During your Main Phase: You can banish this card from your GY, then target 1 "Regulus, the Prince of Endymion" or 1 monster that mentions it in your GY; Special Summon it. You can only use each effect of "Arrow of Regulus" once per turn.