what paper are you using?
that can cause problems

110 lb Cardstock.

try smooth bristol.
that's what I use
http://www.furaffinity.net/view/5384585/
it streaks a little no matter what

Looks fine to me.

very good^^

Actually, the overstroking on the tunic rather makes it look like a primitive tanned leather...

yea I can see the parts with multiple strokes and even a few pressure points. Looking at the left bottom foot, the varying shades really adds to the level of detail, even to an extent to realism which can definitely be useful.

Markers take a long time to get used to and as others pointed out, the paper makes all the difference. I tried em once and traded em for colored pencils for the little art I used to do. (Colored pencils just to me are alot nicer ^^)

I used to work in markers a lot. I don't think I was ever terribly good with them, but I did learn a few things. Like overstroking can be minimized if the ink on both sides is still a little wet, causing the ink to bleed into itself and mellow out a little.

You'd do better at markers if you weren't sniffing them.

A swordsman with modern grenades? Awesome.

The trick to using markers is to not stop applying color until the whole area has been filled. If the ink dries then it will create the hard edge you see in your picture even when using the same marker next to it. What you need to do is go over the same area again and again a few times until the space is saturated and "wet" and then when it is uniformly covered it will dry in a singular shade without visual brush strokes remaining. That's one of the drawbacks of markers; it is very, very hard to do large areas of color consistently since your brush tip will start drying out before you're finished even if the marker reservoir still has capacity left to go.

Good show!