Maleficent… which is like the most copout answer ever, but the fact is that she just really hasn't bonded to any Personae besides Mal and Beauty. I should probably throw her at some others, but just going down the list, I don't really see any that strike me as OMG YES THIS WOULD BE BEAUTIFUL. I wasn't even really expecting her to hit it off with Mal, though, and now she is just kind of ♥ Mal ♥ and has this fierce loyalty thing that I didn't anticipate at all. I can potentially see her going with Jacobi, though, if she absolutely had to pick, depending on how threads with Jacobi went/whether there were any trauma games. (Trauma games pretty much automatically rule a Persona out as someone she would willingly do favors for.)

If ASCH could take a Persona patron, who would he pick? :3