Seeking advice on MHX Vile Running sprites

[yesilovenachos]

Hello, prestigious pixel patrons,

I've been working on a project these past several months involving particularly edgy Mega Man X character Vile - all of this being based on an unfinished endeavor from a user on DeviantArt [just some tragic backstory].

Recently, I've run into a problem of shading (which always has baffled me.), and creating perspective with the movement of the cannon that would sway left to right during the character's motions.

Is there a reference or tutorial I could be directed to? None of the questions I've asked in the faithful search engines has yielded results, for those quick to mention our dear friend Google.

Thanks for any who can help.

[yesilovenachos]

Undaunted users,

I have made progress since my last post, despite the staggering lack of input. I hope you all enjoy this. It's by no means perfect, but I've had fun making it, and that's what matters.