: Forrest mentioned above that Tycho is described as a "smug
: intellectual", however, so I could be wrong.
That's not necessarily contradictory: the people at the top of a hierarchy usually aren't so smug or condescending at the people *near* the top of the hierarchy. The people at the top have nothing to prove: the evidence of their superiority is plentiful, and it doesn't matter if anybody else sees it or not, they're sure of themselves. The closest to smugness is just the self-confident dismissal of what they perceive of non-threats, as Durandal often treats the Pfhor, and the casual treatment of inferiors as personally uninteresting tools to be used to one's own ends, as Durandal treats humans and (to a slightly lesser) extent the player-character.
But those a little ways down the latter are in the shadow of their superiors and always feel the need to puff themselves up and tear down those above them. Tycho needs to make it clear that he is your superior, superior to those damn humans who never gave him the respect he deserved, superior to the stupid bugs who think they can control him even now, and definitely superior to that damn Durandal who thinks he's so hot shit. Tycho has something to prove. Durandal doesn't need to prove anything; he's just pursuing his dreams, little people be damned.
Back to art: I always imagined Leela as a friendly but slightly mannish woman (squarish head, broad shouldered frame, tall, etc). She's the boss, she's in charge, she's big and strong, but she's still female.
Durandal we have a reference pic for - his chapter screen from M1. I agree with the comments about him having a smirk, at least post-angry-stage. I have an image of him in my head as that kind of person who never really acts like anything's a serious problem, always has a positive, self-confident outlook; almost like a Steve Irwin type, but much less exuberant. Still, you get the quieter version of "Crikey! A massive Pfhor battle fleet just folded into the system and started attacking my single ship! It's all right though, cause I've modified my weapons to outmatch their range.... Crikey! It seems I've been forced to crash land on an alien moon and my ship is being boarded! It's all right though, cause..." There's never actually reason to be worried, cause Durandal is the ultimate chess master and knows that though he sacrifices all these pawns, he will take the queen in the end... at least, until the start of Infinity when he realizes the universe doesn't have to play by such nice rules.
Tycho I picture as older-looking, with a rounder face than others; biggish cheeks and such. Possibly glasses, maybe a nice well-groomed beard or moustache, receding hairline or possibly even bald (heck, Durandal is bald). I'm drawing a lot of this imagery from his role as a scientist, and his namesake Tycho Brahe.
