If only your opponent controls a monster, you can activate this card from your hand. Special Summon 1 monster from your hand (but negate its effects), then if your opponent controls a monster Special Summoned from the Extra Deck, you can Special Summon 1 "Synchron" monster from your Deck. Until the end of the next turn after this card resolves, you cannot Special Summon from the Extra Deck, except Synchro Monsters. You can banish this card from your GY; immediately after this effect resolves, Synchro Summon 1 Synchro Monster. You can only activate 1 "Synchro Emergency" per turn.