REDU format ruling
Lightforce Sword

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)Banish 1 random card from your opponent's hand, face-down. During your opponent's 4th Standby Phase after this card's activation, return that card to their hand.
Rulings
- If you chain Lightforce Sword to your opponent's Ritual Spell Card and remove from play the only Ritual Monster they could Ritual Summon, the Ritual Spell Card's effect disappears.
- If the Standby Phase of your opponent's 4th turn is skipped, the card remains removed from play face-down.
- If your opponent adds 1 of your Spell Cards to their hand with Graverobber and it is removed from play with Lightforce Sword, during the Standby Phase of your opponent's 4th turn it is placed into your GY instead of your opponent's hand.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.