Scatter Fusion - 25th Anniversary Tin: Dueling Mirrors

During your Main Phase, if your opponent controls a monster: You can Fusion Summon 1 non-Rock "Gem-Knight" monster from your Extra Deck, using monsters from your Deck as material, also you cannot Special Summon monsters from the Extra Deck for the rest of this turn, except "Gem-Knight" monsters. You can only use this effect of "Scatter Fusion" once per turn. When this card leaves the field, destroy all monsters Summoned by this card's effect.