Hi ricardosohn, finally checking out your thread,
It looks like you have ways to go, but this axe shows promise
If you find it hard to draw monsters, try taking some monster sprite that already exists as an underlayer, and using it as a reference for the perspective of your own monster.
The helmet is getting better and better, I can see you're learning.
The armor is way too shiny, with transitions from dark to bright colors being very rough and sudden, making it look more like only an outline that was filled with a single color.
It definitely has room for improvement.
Always try to start out with filling the outline with darker colors, then applying lighter colors inside to
draw your details in. Once you have a 'map' of your details, you'll get the intuition how to work around popping those details out.
And don't be afraid to use dark colors for something that is supposed to be shiny. If you take a look at my
video where I teach how to draw shiny gems, you'll notice that half of the gem is filled with a very dark color. You may get a feeling of how to deal with crystals if you watch that video, if that's something you might want to learn.
I did a quick remake of your armor (if you don't me using it as a base) to show you an example of what you could get if you flesh out the contrasts more and work around putting more effort into the details. It can certainly be improved more, but it should be enough for you to zoom in and study some places on the sprites that may interest you, to see how it's done.
Cheers, hope to see you post more!