Elemental Hero Magma Neos

"""Elemental Hero Neos"" + ""Neo-Spacian Flare Scarab"" + ""Neo-Spacian Grand Mole""This card cannot be Special Summoned except by returning the above cards on your side of the field to your Deck; then you can Special Summon this card from your Fusion Deck (You do not use ""Polymerization""). Increase this card's ATK by the number of cards on the field × 400 points. This card returns to the Fusion Deck during the End Phase. When this card is returned to the Fusion Deck by this effect, return all cards on the field to their owner's hands."