Well some builds Dread Return Cephalid Sage or Ashen Rider.
This could also play cards such as Living End, correct?
Yeah living end and other suspend cards are probably the only cards worth flashing back. This may be worth looking into. Living end alone has the potential to tighten up the win con for Dredge substantially.
Edit:
It's worth noting that living end can win through Grafdigger's and containment priest.
I don't think Living End gets thru containment priest. Grafidiggers yes. Priest no. Relevant card text:
Living End: Each player exiles all creature cards from his or her graveyard, then sacrifices all creatures he or she controls, then puts all cards he or she exiled this way onto the battlefield.
Containment Priest:
If a nontoken creature would enter the battlefield and it wasn't cast, exile it instead.
Grafdiggers Cage:
Creature cards can't enter the battlefield from graveyards or libraries. Players can't cast cards in graveyards or libraries
Notice the difference in effect of grafdiggers and priest? One stops cards being cast from graveyards or entering the battlefield from graveyard. Living end does neither of those. The priest though stops any creature not cast from entering the battlefield so it would stop living end from bringing creatures into play since you aren't casting them.
Living end works when a containment priest is on the battlefield. The containment priest would be sacrificed before the creatures are put from exile onto the battlefield.