This is turning out nice, keep it up. So this is some off-the-cuff feedback for ya,
I feel that the colors are too desaturated. I believe greentooth is taking interest from your painting, he's looking pretty generic, I think, if you wanted to have greentooth in there, you should try and redesign him to match your character more. What you have here is a classic example of "contrast in detail". When I wrapped my head around this concept, it really was an ah-ha moment for me. You may have already known about it, but the idea that contrast wasn't just white vs black... that there were NUMEROUS design elements to find and use against their opposites and overlap their effects with another to create interesting movement in composition. I feel that your detail work is pulling the eye downward. Typically I've found, when it just comes to viewing ornate detail, I'll see silhouettes first, ignoring highly detailed areas, moving to less detailed areas and once I'm more familiar, I'll search the details. I just wanted to bring that thought I was having to light.
If I were attempting to paint this, I'd become bothered having to paint through sketchlines, especially lines as ornate and detailed as yours. Two approaches I use for something like this, hoping your lines are on their own seperate layer, I'd tint the lines to a color that isn't as jarring as black line, red typically works well, but since there are cooler colors being used here I'd try green or blue. The idea is that the lines won't be as noticeable if I miss them with a brushstroke, the goal is to turn the sketch into a painting, so you have to render in such a way the lines become apart of the painting...
A second approach, I'd copy and hide the sketchlines so I'd still have them if I needed them (there is good detail info you've sketched in there) I'd blur everything a tad and start painting overtop it all.
Again, great work so far, nice display of good draftsmanship, The tenticles turned out rad.