Straight out of Neo Space!

If only your opponent controls a monster, you can Special Summon 1 "Elemental HERO Neos" from your hand, also for the rest of this turn, you cannot Special Summon, except "Elemental HERO" or "Neo-Spacian" monsters. During your End Phase, if a Fusion Monster you control is returned to your Extra Deck, you can Special Summon 1 "Elemental HERO Neos" from your Deck.