I have to echo the statements others have made. Too many pictures of half-orcs lean towards emphasizing the orcish appearance, forgetting they have human in them too. And I have a soft spot for paladins, so I like this even more! Kudos!
I love this character too. He really has the strong and pure stare one expects in a paladin, which makes him something different from a simple warrior and still he's not the cliché prince charming as some paladins are. Also a brilliant study for an orcish halfbreed!
I always try to give my characters "an edge", preferably multiple ones, and flee away from anything resembling tradition or cliché. It's impossible to present every quirk in one portrait, of course, at least by my raw and self-learned skill, but I do my best.
Trivia: Children make Sir Nothgar lose the strength in his voice, for he still remembers harsh bullying he once suffered, and his greatest challenge then is to keep his stammer in check. Sure, Nothgar was the biggest kid, but he also had too much natural gentleness - and religious fear invoked by his virtuous Silver Flame tutors - to defend himself. Today he can easily handle a monster, but when it comes to mostly innocent nuisances...