I don't have my tablet with me, so this is just going to be words this time.
First, about your picture:
1) If you still have it, I'd like to see various stages of your work and also a screencap of your coloring process so I can see it and give you feedback on that, but from what I can see you're restricting yourself to various shades white and black for highlights and shadows. That can work in some circumstances, but I would encourage you to experiment with more tools, layering effects, and colors.
2) Black sclera + black irises = I can't make out his eyes at all. I would suggest making the irises red so that they can contrast.
3) Are you planning to shade in the rest of the picture in addition to drawing the buttons and pockets? With only the head shaded, the picture looks unfinished.
4) Your character's head is a little bit too big for his body. Adult males generally have shoulders two to three times wider than the head. Also, although he's standing at an angle, the two sides of his body should be a little bit more even.
5) The ears are too high up in his head, even for pointed ones. They should line up with the corner of the eye at the top and the bottom of the nose.
Second, some teal dear about your oc's character design:
1) His face is super generic (having the sides of his face obscured by hair doesn't help, nor is it a particularly practical hairstyle given that he's supposed to be wearing a balaclava at all times). If you're not planning to have your character look like the Spy, I suggest you google something like "male face shapes", "male head shapes", "male nose shapes" etc.
2) His facial proportions do not make him look like an adult male. Again, I suggest you use google to help you reference what average real-life proportions and then work from there--and don't forget that TF2's dudes tend to have exaggerated jawlines.