I think Circe should be to Hippolyta what Barabra Ann is to Diana: former friend turned bitter rival. They should have their own epic backstory of friendship and betrayal. And I always imagine Circe's early encounters with Diana (and, in an ideal world, Donna as well) would be more about striking out at the queen's daughter(s) out of spite for not being able to get at Hippolyta herself. And of course, after repeated encounters, she's going to develop a complex rivalry with Wonder Woman herself.
I'd still have to check out how Tynion ironed it out. The take I didn't find interesting was Perez's, but maybe Tynion's would work for me.
Also, I always liked her design in your avatar. I wish that would make a comeback, none of the others really work for me. The early Rebirth one was fine for interacting with mortals but not as her default, and I hate the New 52 one where she looks like Goth Pipi Longstocking.