If this card is Normal or Special Summoned: You can add 1 Spell/Trap that mentions "Ancient Fairy Dragon" from your Deck to your hand. During your Main Phase: You can Special Summon 1 Level 4 or lower LIGHT monster (Beast, Plant, or Fairy) from your hand in Defense Position. You can banish this card from your GY, then target 1 Field Spell in your GY; place it on the bottom of the Deck, then draw 1 card. You can only use each effect of "Regulus the Fairy Beast" once per turn.