Mystical Celtic Sage

If this card is Normal or Special Summoned: You can activate this effect; you can only Special Summon from the Extra Deck once for the rest of this turn, also reveal your entire hand, and if there is a card that mentions "Ritual of Light and Darkness" in it, you can draw 3 cards, then discard 2 cards. You can Tribute this card; Special Summon 1 Ritual Monster that mentions "Ritual of Light and Darkness" from your hand. You can only use each effect of "Mystical Celtic Sage" once per turn.