I'm also excited for more mages, because we shall take over group one, mwa-ha-ha-ha-ha-ha--ahem, I mean, I can't wait to see what happens when Imenry's Wonderful Old Friend meets Imenry's New Kind of Co-Dependent Tiny Friend. ... worst case, I think poor Signy could develop some jealousy and "I'm being replaced bawww" issues, but I think that depends on how things go down when everyone reunites after the current scenes. She's also scared of new people, but he seems really friendly so there's a good chance they could get on well, too.
If they do get along, however, and this is just a random idea, but: Signy totally needs a, like... mage-stuff mentor. (Especially since, not gonna lie, I wanted her to eventually pick up the Battlemage specialization for Signy and oh man look a teacher. I am so shameless.)