Elemental Hero Air Neos (STON-EN034) [Strike of Neos]

"Elemental Hero Neos" + "Neo-Spacian Air Hummingbird"
<br>This card can only be Special Summoned from your Fusion Deck by returning the above cards you control to the Deck. (You do not use "Polymerization".) While your Life Points are lower than your opponent's, this card gains ATK equal to the difference. This card returns to the Fusion Deck during the End Phase.