If you control a DARK Dragon Link Monster, you can Special Summon this card (from your hand). You can only Special Summon "Rokket Detonator" once per turn this way. You can target 1 DARK Dragon Monster Card in your Spell & Trap Zone; Special Summon it (but it cannot attack, also its effects are negated), also you cannot Special Summon from the Extra Deck for the rest of this turn, except DARK monsters. You can only use this effect of "Rokket Detonator" once per turn.