Card Rulings:Humhumming the Key Djinn

OCG Rulings

 * "When this card is Special Summoned: You can target 1 "Djinn" Xyz Monster in your Graveyard; Special Summon that monster, then you can attach up to 2 cards from your hand to it as Xyz Materials." effect is an optional Trigger Effect. (This effect targets 1 "Djinn" Xyz Monster in your Graveyard. It can be activated during the Damage Step. When this effect resolves, applying "Special Summon that monster" is mandatory, but applying "attach up to 2 cards from your hand to it as Xyz Materials." is optional.)


 * "Once per turn, during your Main Phase 1: You can detach 1 Xyz Material from this card, then target 1 "Djinn" Xyz Monster you control; that monster can attack your opponent directly this turn." effect is an Ignition Effect. (This effect targets 1 "Djinn" Xyz Monster you control. Detaching 1 Xyz Material from this card is a cost to activate this effect.)