I never read the comics, so my only impressions of him were from Season 1. Even in Season 1 not much was disclosed about him, but the dude is Abraham Lincoln. I always thought of him as being wise, amiable and good natured. Now he just kind of seems like an asshole, and that whole hooking up with Kate thing definitely brought his moral code down a few pegs in my eyes. I can’t blame his misgivings about Invincible, but why is he a jerk to everyone else? Maybe you just stop caring after a couple millennia.
He’s a hard-ass which is exactly what the Guardians need. Though Dupli-Kate should obviously be relieved of her position as a field operative since you can’t have teammates in a romantic relationship with each other, especially between a superior and a subordinate.