23 and 27 for freiderick?
What is your OC like when they are angry?
It depends a little bit on why and what he is angry about! When somebody is pissing him off he can get snappy and passive aggressive but sometimes he also starts stonewalling people, which isn't always helpful because that often just leads to the constant anger boiling under the surface to just make him mean and irritable - which often leads to just getting even more angry with people.
What are some assumptions others make about your OC? Are any of them true?
Assumptions have been made about him by other characters plenty before! Vincent, who only knew him as the friend of Kade who never stayed and then disappeared, assumed him to be a selfish asshole basically - and it has been fun to see her getting kind of irritated that now that she met him... he just isn't the big evil guy she pictured him as.
While he has issues and a tendency to be avoidant, he is mostly just a guy who is trying and cares deeply about his friend Kade but needs to maybe get better about considering other people's feelings.
Another character has made assumptions about him based on his work as a sailor (and his own experiences with them) that didn't prove to be right. There is also thinking that he doesn't care as much as he does, he isn't very expressive outwardly and that makes him hard to read for people sometimes.
In general, because he also tries to put on that aura on purpose, people can assume he is a lot more austere and stand-offish or outright harsh than he actually is. He definitely has his moments - and he struggles with being relaxed and comfortable around people in a way that probably often does look stand-offish but he is also someone who tries to look out for people and likes to make his friends laugh with witty little comments.