Advanced format ruling
Ancient Sacred Wyvern
Card effect (current official text)1 LIGHT Tuner + 1 or more non-Tuner monsters
While your LP is higher than your opponent's, this card gains ATK equal to the difference. While your LP is lower than your opponent's, this card loses ATK equal to the difference. When this card is destroyed by battle and sent to the Graveyard: You can pay 1000 LP; Special Summon this card.
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.