So, since we're coming up to the turn where we need to decide; let's try to do a final check up on our 2 mage options.
Dr Orpheus:
From Venture Bros, Orpheus is probably one of the nicest and least awful people in the show. While officially a Necromancer, he doesn't actually specialise in Necromancy; though he can do it. He just chose the name since it sounds cool. Member of the Order of the Triad, he is a hero; though depending on when in the Venture Bros timeline we are their Arch, Torrid, might be dead. He also has a decently good relationship with his daughter, even if he keeps mind wiping her. He's an all round magical powerhouse, who's primary cons are that depending on how evil we act and what actions we take he might lose loyalty. I also question how much he'd approve of joining the Guild, but the lack of an active Arch means we probably won't have any paperwork shenanigans (If this is before Torrid died we might have some issues).
Hex:
From Ben 10, Hex is a refugee from the magical dimension of Legerdemain, with his niece Charmcaster being his accomplish in his earlier career as a supervillain. Abusive to her and very easilly angered, over time Hex's attitude was tempered out, becoming less hot-headed and less abusive to his Niece. Eventually he retired from Supervillainy and became a College Professor, though that hasn't happened yet. He practices Dark Magic, mostly offensive, and has an incredible knowledge when it comes to Artifacts. His biggest weakness is that depending on when in the timeline he is, he could be a complete jerk.
I personally am leaning on Hex, but won't be to to beat up with we do Orpheus.