Tengu format ruling
Fusion Gate

Card effect (current official text)While this card is on the field: The turn player can Fusion Summon 1 Fusion Monster from their Extra Deck, by banishing Fusion Materials listed on it from their hand or field.
Rulings
(1) As long as this card remains face-up on the field, a Fusion Monster can be Fusion Summoned without using Polymerization. The Fusion Material monsters used in the Fusion Summon are not sent to the GY, but are removed from play.
- The (1) Ignition-like Effect activates & resolves on the field.
- Both Players can activate this effect on their turn.
- This effect can be activated more than once per turn.
- There is no activation cost. Fusion Material monsters are banished when this effect resolves.
- This effect can be negated by Royal Oppression, and this card will be destroyed.
- Fusion Summoned monster can later be Special Summoned from the GY / banished.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.