Kefial seems like a person with a good command of aesthetics and design elements, and a wonderful ability to use color palettes effectively (you know the sort...like...you walk into their home or apartment and everything looks so well put together in an appealing, refreshing, and totally cool way). It also makes me think that at the very least Kefial looks like they've got their s**t together irl even when they might not really feel like they do.
Kefial seems sensible and direct and probably as blunt and upfront as the no-nonsense design of their avatar would suggest. If something needs to be said, they'll say it, regardless of whether it'll hurt someone's feelings or not - if feelings are hurt, too bad, deal with and move on, or go somewhere else.
The grin gives me the impression that Kefial's the type of person who likes to raise Hell every so often, not in a mean way, mind you, but in more of a 'Why yes, I am a little s**t on occasion, thank you for noticing' sort of way. That's sort of fun.
In short: Kefial is pretty neat.