Advanced format ruling
Cyber Dragon Zwei
Card effect (current official text)If this card attacks an opponent's monster, it gains 300 ATK during the Damage Step only. Once per turn: You can reveal 1 Spell in your hand; this card's name becomes "Cyber Dragon" until the End Phase. This card's name becomes "Cyber Dragon" while in the GY.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.