Beastie, your post for reducing colors and producing alternate pals is exactly what I was going to point out in the end for critiquing.
Itsuchi, here's my critique which I'm going to comment after I looked at 2DWillNeverDie tutorial on how Kiwi did. It's about the white or grey part you grey-scaled after shading. You left plenty pixels without reducing to a few colors after you drew and grey-scaled it. I dunno what program you're using and I don't want to dog your sprite but I just observed over your processed sprites and Beastie's remap edits by opening to Paint, and I gotta say like I said, you missed reducing to a few colors like 5 or 6, and cleaning/sharpening the sprite up before coloring. His white shirt looks like you left it to be uncolored. Maybe you can change to some different white color tones I think. Otherwise, it's okay. For Beastie's part on the remaps, he did great for reducing to 16 colors but after it's reduced, there are some grey color pixels on both of his fore arms. I don't blame Beastie for that because we dunno your technique of working on sprites.
Conclusion: I'm going to say you did very well in following the tutorials, but only one step you missed was sharpening and cleaning by reducing to a few colors and making pixel fixes before coloring. I think you can refix your sprite after coloring so that you can make it as a final outcome. I don't like to make it sound harsh or like an insult, but from my point of view, I just wanted to let you take a look of what/how you process your own work carefully. I'm not a perfect spriter like you but we practice from our own mistakes.
I critique sometimes though.