I agree with that that too about whether gender may also lead to what type of familiar will be summoned. True, so far we've only seen male familiars who were summoned by void magic users have the rune powers similar to gandalf and if a female familiar was to be summoned, then they'd more likely have void casting magic and items. It'd be interesting to see whether Tiffannia will summon a familiar or not as well as what type it is depending on personal traits, appearance, gender and Interactions I believe.
Well, Im sure we'll get to see more characters like that blue hair girl up ahead and who knows whether she has void magic, different types of magicor not magic at all.