Advanced format ruling
Criosphinx
Card effect (current official text)When a monster is returned from the field to the owner's hand, the owner of the returned monster selects and sends 1 card in their hand to the Graveyard.
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.