Advanced format ruling
De-Synchro
Card effect (current official text)Target 1 Synchro Monster on the field; return that target to the Extra Deck, then, if all of the monsters that were used for the Synchro Summon of that monster are in your GY, you can Special Summon all of them.
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.