This card's name becomes "Dark Magician" while on the field or in the GY. You can only use 1 of the following effects of "Dark Magician, the Pharaoh's Servant" per turn, and only once that turn. If this card is in your hand: You can reveal 1 Spell in your hand; Special Summon this card, then you can Set 1 Spell/Trap that mentions "Dark Magician" from your Deck. (Quick Effect): You can discard 1 Spell; destroy all Spells/Traps your opponent controls.
