... I hate to be the guy to say this, but it hasn't improved at all.
Light source is all over the place on the leg, leg movement looks erratic (when landing the punch, the leg shifts position unnaturally), and there are proportion/animation inconsistencies. One part of Bardock's armor disappears, he becomes skinny when he lands his punch (that shouldn't happen at all), and hair feels kind of stiff when the animation goes.
Here's something I whipped up quickly (it's not perfect I know, twas really quick):
Notice how it all goes a bit smoothly now? And with more refinement, it can be professional looking, Z2 quality.
I have the following to suggest for you: take a break from this project, a small one, and just practice the concepts associated with it: lighting, outlining, animation (This article and this video are great), coloring, etc. For your sake, let's say you are only interested in Z2 spriting. Which is totally fine. Do the above, but with the Z2 style in mind. See how Balthazar handles lighting on his sprites, see how he handles outlining and anatomy, and see how he handles animation. Look up all the sprites from his Z2 project threads, save em, and study them.
Practice doing Z2 sprites on easy subjects, then move onto harder ones. Make sure you can at least do those things (single sprites speaking) before moving on to animation. Once in animation, study how change occurs. By this, I mean literally go through Balthazar's sprites and see how an animation was handled. Look through HQ and Barker's animations and see how something changed from one frame to the other, all the while keeping the 12 principles of animation in mind (and see how those apply as well!).
Another thing, well these:
Some behind the scenes stuff to show part of the sprite creating process.
Spoiler, click to toggle visibilty
Consider using stuff from other games, and or tracing if need be.
I mean, I hate tracing (I think you didn't want to work over Goku because you want to learn scratch spriting), but if it gets you viable results do it. And hey, Balth is pretty professional, and professionals do it, so why not you? Something to think about.