If you watch Rythian's series, Duncan feels like the villain, through and through, but in Duncan's series, he still plants the nuke and stuff, but Rythian still feels like the bad guy and he agrees to teach Kim for absolutely free and doesn't set up any emergency procedures when she became potentially dangerous.
I love the really quite massive height difference between Rythian and lalna in your designs for them. The tall, thin figure fits Rythian's grim, brooding, tortured personality, almost making him seem vampiric, and Lalna's general squal stubbiness fits his happy-go-lucky but still rather monstrously evil persona. I could just see Rythian standing at a window with a wineglass as it's raining, while elsewhere Lalna is waddling around his lab, whistling a tune and plotting some sort of atomic Armageddon.
Also, Zoey and Rythian hiding under the cape-tent is just so adorable! It makes me want to squee! I love how Zoey is able to bring out the joyful and childish side of Rythian (sometimes).
I actually like your concept of Zoey, it fits her personality. But Duncan is the best. He look so evil and be is probably scheming something behind his back... Maybe an army of chickens to invade sick bay? >
...If anyone would be fat I thought it would be Rythian since theres an IRL picture of his head and boy does he look chubby! Amazing work but next time you should make Zoey skinnier...much skinnier....