Edison format ruling
Energy Drain
Card effect (current official text)Target 1 face-up monster you control; it gains 200 ATK/DEF for each card your opponent currently has in their hand, until the end of this turn.
Rulings
- When Hayabusa Knight, boosted by Energy Drain, attacks, and the opponent's hand is reduced during the battle, the ATK of Hayabusa Knight for the second attack is not changed because the effect of Energy Drain is determined when Energy Drain resolves.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Edison forum — sourced change requests get reviewed.