I think that it's been made amply apparent how much of a witch-with-a-b that Malice is. BFFs with a chaos deity... not bad, but Sonia'd better watch her back, 'cause that gig didn't work out so well for Odin and Osiris.
It would be an interesting twist if Luna's Slayer X form, if it exists after your revamp, turned out to be a "gift" from Mysti to Sonia - the "well-meant but poorly thought out" kind of gift. Most likely not the case, but I still think it would be an interesting twist.