Nothing wrong with that. If you're not feeling it, no need to force it. You can always retry again.
And since you asked, I can usually rant for a bit when it comes to some of this stuff xD.
I guess there are different technical points that could be worked on, some of them minor, some of them bigger.
When it comes to action, exageration and foreshortening help a lot, so exagrating the pose and expresion almost to the point of deformation, could help. You focus on what you are trying to convey, and then try to see how the different elements help convey that goal. For example, from my understanding, he's being attacked and is seconds from disaster, since his expression should show he has no recourse. So perhaps exagerating to pose to show "vulnerability"/"tension" and the expression to show "shock" and "fear".
Talking about foreshortening and action, you usually want to keep the camera close to make the viewer feel like they're in the middle of it, which makes things more exciting. Keeping the scene inlcined also helps.
Also for action, you usually also want the lineart to be part of the expression, usually you can add action lines across the lineart to make the flow more evident. Same goes for coloring. There's also a bit of white around, but I take it the piece is simply incomplete.
All in all, here's a quick example to illustrate the whole foreshortening and action stuff using your piece as a reference.
There's no horizon, so can't really tell if it's standing or inclined, but the gesture is as diagonal as possible. The front is open to seem like he's vulnerable (open vulnerable, closed protected). Then there are the obvious points like the hands foreshortening and exagerated expresion, almost comical. I also put the fireball closer to give it a bit more tension.
Granted, these are just general tips, there are no hard rules, and your work to the eyes of someone who hasn't been looking at it for hours looks pretty good.
