Tengu format ruling
Zombie World
Card effect (current official text)All monsters on the field and in the GYs become Zombie monsters. Neither player can Tribute Summon monsters, except Zombie monsters.
Rulings
- Players can still Tribute Set non-Zombies while this effect is applying.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.