Seeing that there is a chance these two will return, wouldn't it be awesome if these two were able to dish it out in an ultimate battle of villains. Evil vs. Evil. Monster vs. Monster. Changeling vs. Umbrum. In an old classic Alien vs. Predator/Freddy vs. Jason/Skrull vs. Kree style smackdown.
Scenario: Chrysalis and her changelings attempts the invade the Crystal Empire. In desperation, the Crystal Ponies revives Sombra in order to save their empire. Sombra's uncovers his Umbrum army to fight off against Chrysalis's Changeling swarm. And the best part, Sombra may have a advantage. Since his heart is filled with hatred, he can be immune to Chrysalis's love absorption, forcing her to fight him on equal terms.
Personally, I'm rooting for Sombra.