The thing is he is NOT helping them (as far as I know) they're helping HIM. After all Yuga Khan, father of Darkseid is supposedly main villain in Odyssey and he is one of those beings that Darkseid is afraid of, a guy that could KILL Anti-Monitor. Darkseid NEEDS to get rid of him and for now without his peak power he has to ask for help. And probably backstab this team so hard the knife will go all the way trough their bodies. God of Evil title stands for something.