If this card is in your hand or GY: You can discard 1 "Crystron" card, except "Crystron Sulfefnir"; Special Summon this card in Defense Position, then destroy 1 card you control. If this card on the field is destroyed by battle or card effect: You can Special Summon 1 "Crystron" monster from your Deck in Defense Position. You can only use each effect of "Crystron Sulfefnir" once per turn.