I wonder if its possible the ball they are holding is the dark curse orb. It’d make sense if Hades created it. Maybe he and Rumpel met at some point in the past and discussed it. There seems to be a flashback of DO Rumpel talking to someone.
[adrotate group="5"]
"I could have the giant duck as my steed!" --Daniel Radcliffe
Keeper Of Tamara's Taser , Jafar's Staff, Kitsis’s Glasses , Ariel’s Tail, Dopey's Hat , Peter Pan’s Shadow, Outfit, & Pied Cloak,Red Queen's Castle, White Rabbit's Power To World Hop, Zelena's BroomStick, & ALL MAGIC