John has been around for two years, going into his third, so it's likely that he knows people who aren't brand new to the school. I think I've played with all youse guys, so you know what he's like, but if not: abrasive and snarky, very likely to call your character out and try to pick a fight, not averse to outright bullying. And using fire. Someone who can keep up with or outpace him in troublemaking and disdain for the world/the school could've become more pleasant acquaintances with him over this time, although friends is unlikely and would be easier and more fun to build through actual CR anyway.

Dulcie is a brand new teacher, carrying English and Physical Training! She's extremely serious and self-motivated, on the strict side, can get lecture-y (not always scolding, sometimes just trying to impart lessons she wishes she got as a teenager), but also has a somewhat dry and self-deprecating sense of humour that can be brought out by the right person and a lot of warmth waiting to be revealed to students who inspire it. All CR will be new, but if you've got ideas, go nuts!