First Attempt for Realism...

My first realistic style character for a... Too long time (can't really recall any before this..). As soon as I got it scanned I noticed that the hands are perhaps too long and the muscular system on stomach look wierd. Any other big flaws on this in your opinion so I can train on them..

Picked demon hunter for it's good view on muscles, but left those tattoos away intentionally.

there's a big proportion problem with the arms and the legs. Remember that the body must be 7 times longer than the head. The right arm is too long, and the other too short, but it may be the perspective...
Work more for the face. The ear is misplaced...
V'ery good job!! keep it up!

INFERNAL ROXZOR!!!!

i think you shaded too much on the muscles. it almost looks as if he doesnt have any skin, and only muscles are showing. Just keep working on it...and take the shading down a notch or two.

Well, yes the ear is a little misplaced; it should be bigger also. The main issue is that the shoulders are too thin IMO. Also the upper torso looks flat and taken from the wrong position (it should be 3/4) it's difficult to explain it in words, though. I took the liberty to edit your picture.