I don’t know Grail. How would we explain how one hooks up with a Darksied?
Grail's mother was, i think, raped by Darkseid. She kept Grail in order to destroy Darkseid. It didn't work that well. Darkseid is, after all. It's explained in Darkseid War. i recommand you read it if you didn't, because a lot of things happening in Darkseid War are the foundation of what we have in rebirth wonder woman. I re-read it sometimes because it is a very good story.