Failure / Comply
1U // W
Instant // Sorcery
Failure
Return target spell to its owner's hand.
//
Comply
Aftermath (Cast this spell only from your graveyard. Then exile it.)
Choose a card name. Until your next turn, your opponents can't cast spells with the chosen name.
This just occurred to me. I wonder if Comply is a good card for Dredge. It's almost like an extra Cabal Therapy that you can cast from the graveyard, although obviously worse since you actually need mana. But maybe having 8 spells to help you resolve Dread Return is good.
The card itself is not bad and reminds me a bit of Reflector Mage if you play it in a control build. Probably worse than Unsubstantiate and Remand in that role, though.
But do you think Dredge wants this? Seems good.