Tengu format ruling
Elemental HERO Divine Neos

Card effect (current official text)Must be Fusion Summoned using any 5 "Neos", "Neo Space", "Neo-Spacian", or "HERO" monsters, including at least 1 "Neos" or "Neo Space" monster, 1 "Neo-Spacian" monster, and 1 "HERO" monster, and cannot be Special Summoned by other ways. Once per turn: You can banish 1 "Neos", "Neo Space", "Neo-Spacian", or "HERO" monster from your Graveyard; this card gains 500 ATK, and until the End Phase it also gains the banished monster's effects.
Rulings
- Removing 1 Neos, Neo-Spacian, Elemental Hero, Destiny Hero, or Evil Hero monster in your GY from play is a cost.
- You can remove from play a Normal Monster Neos or Elemental Hero monster to activate the effect of Elemental Hero Divine Neos. In this case Elemental Hero Divine Neos will not gain any effects.
- If you use Elemental Hero Neos as a Fusion Material Monster, it can be used as a Neos monster or an Elemental Hero monster, but it cannot be used as both at the same time. If you use it as a Neos monster, you will still need another Elemental Hero, Destiny Hero or Evil Hero monster.
- If you remove Evil Hero Dark Gaia to activate the effect of Elemental Hero Divine Neos, the original ATK of Elemental Hero Divine Neos' does not change.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.