I suspect if you had some sort of "gender-meter" that you could point at someone and it would tell you objectively what gender-category best fit them, it would place Ellen outside or between the "male" and "female" categories (in whatever category "gender-meh" was labeled as). However gender is such a personal issue that I think how a person chooses to label themself (or not label themself) is far more important than what a gender-meter would tell you - and not just because there's no such thing as a gender-meter.
Magus is extremely insistent he's male - so much so that I'm sure he's not gender-meh, and is somewhat insecure about his gender or how people perceive his gender; it's also clear gender has been a source of conflict in his life. This leads me to suspect two possible scenarios: Magus identified as female as a child and still feels female inside, and is trying to convince himself he made the right choice, OR Magus has always identified as male but no one respected or believed that and when he finally got the chance to transition he had to come up with some sort of justification for why he was doing so. I'm not sure which is more likely.
Either way, Magus clearly currently wishes to be referred to as male, so until/unless that changes I intend to use male pronouns for him.