[GAME][IN DEVELOPMENT] Sharkaiger (formerly Shark Week)

[Chutzpar]

I think part of the problem with your animation is that he's turning too far back

You posted this yourself so you should be paying better attention to it! Although his upper torso is twisted so it's almost completely facing away, his hips are still sideways to the viewer, so his whole torso is twisting rather than just turning away.
You've shaded the back of your sprite as if he's facing completely away from us, which a- makes the punch seem less powerful (because there's less tension in his torso), and b- gives rise to the readability problems people are talking about.

I think part of the problem is also the lack of transition- I think you might need an extra frame to the spin so it looks more like he's spinning towards us, rather than just raising his arm and punching.