Activates from your Graveyard / Returns from your Graveyard to your Deck
Not a comment in the world. I can see why. The best way to get mileage out of this is a deck based around special summoning with spellcasters. At that point, ya might as well make it dark-magician focused.
It not only has to be sent to the GY as Synchro material for its effect to activate, the Synchro monster you summon specifically has to be a Spellcaster Synchro monster. The only good SC Synchros in DL already have way more reliable ways of summoning themselves than using this card.
All for one spell from GY to the top of your deck, not even in hand.