I think the DK and Kahn could pair up trying to overthrow all realms. Kahn is fading in Outworld and now he'd have a chance at total domination. As would the Dragon King who awakes and (probably) will have that undefeatable army, intent on possesing every realm. So like Shang and Quan Chi in DA they would team up to combine powers and then when they gain control stab each other in the back. Or is that too obvious, I don't know....