A job really well done!
I really like how you didn't make him physically weak, but a tough guy instead of a wimpy geek. Magic is about focus, control and determination, not robes, books and staves.
You showed that real well with the stance, facial expression and outfit. This man has a very realistic look for a rogue mage: he can handle himself and you don't want to mess with him. I love it!
The magic itself is portrayed decently, but it's a little static. It's like the rocks are just floating there while the mage's stance implies that he is moving them, not just making them float. I think a few movement lines would fix that.
One remark: his belt-bag and sword are on the same hip. Isn't it rather impractical to focus all your weight on one side? It can't be good for your balance. Maybe you should move the bag to the other hip? It's just a detail, though. If it'd give you trouble, just leave it.
Edit because double posting is bad.
If you'd like to, I'd love to see you make an example for every discipline to give an indication for them and because having sets would be neat.
I'm thinking of it like this: two rogues, two courts, a male and a female of both kinds. The male rogue performs earth magic, you already showed that one. The female rogue performs fire magic, like a ring of flames or something. The male courtmage would perform water magic, conjuring a wall of ice or maybe a big wave. The female courtmage uses air: she flies by shooting off jets of air behind and below her to stay airborn (it's not graceful at all, though. You're basically just hurling yourself away from your current position rather than glide on the air currents).
If rogues are mercenaries (which is a very fitting comparison, by the way) then court mages are knights. Both can be very skillful and lethal but their styles can differ greaty. Knights train with dummies and wooden swords, mercenaries with cold steel on the battlefield. Mercs have to be crafty, knights are well-supplied. Grittiness versus grace, determined outcast versus well-trained servant.
As such, court mages are more elegant and precise while rogues focus on brutal efficiency. This reflects upon their looks and demeanor (what you did really well here).
Remember though, court mages don't look like pampered bookworms at all. As living status symbols and bodyguards they are trained to be impressive and intimidating.
Of course, it's all just a suggestion so don't feel forced to do this because you can drop it if you don't like it.
Dang, I should put this courtmage-rogue stuff on the magic article
