Tengu format ruling
R - Righteous Justice

Card effect (current official text)Destroy Spell/Trap Cards equal to the number of "Elemental HERO" cards you control.
Rulings
- Count the number of "Elemental Heroes" on your side of the field when the effect of "R – Righteous Justice" resolves.
- There must be enough Spell & Trap Cards on the field in order to activate "R – Righteous Justice". If there are fewer Spell & Trap Cards than the number of your "Elemental Heroes" then you cannot activate it.
- If an effect is chained that reduces the number of Spell & Trap Cards on the field so that you have more "Elemental Heroes" than cards to destroy, the entire effect disappears.
- You cannot pick "R – Righteous Justice" as 1 of the Spell & Trap Cards to destroy for its own effect.
- "R – Righteous Justice" does not target.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.