REDU format ruling
Earthbound Wave

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)When your opponent activates a Spell/Trap Card while you control a "Earthbound Immortal" monster: Negate the activation, and if you do, destroy it.
Rulings
- If you do not control a face-up "Earthbound Immortal" monster when this card resolves, you still negate the activation of your opponent’s Spell or Trap Card.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.