Contrary to popular portrayal of Connor in various fanfics where he is socially awkward and has self esteem issues due to his past, I actually think it would more fun having him be more confident, very strict, a bit harsher than Markus, and very hotheaded. I feel like he wouldn't try to befriend the deviants but rather the other way around and he pushes them away because he feels he doesn't really have much time for socializing due to the active battle still happening. Whereas Markus would be the more calm one and try to talk him out of taking drastic measures.
Other ideas I have would be that Connor frequently spends time with Josh and Simon but the three bicker 60% of the time, sometimes outright getting physical, and Markus and North trying to calm them down with little to no success.
Markus and North often teasing each other (in good fun), and occasionally get playfully competitive (and North usually outmatching him when playing chess). And North often being protective of Markus, proudly being romantic with him.
And also Markus and Connor being brothers and slowly growing closer when getting to know each other better.
