Well this will be my first time critiquing here. I have critiqued before, but it was mostly with fairly 'bad' splices and sprites. So to do it here, is harder due to the better polish on all the sprites around. I have to say though you're style is very nice, a very deep use of scratching and fusing. A lot of your things look like they are fully scratched. So the stuff I'm about to say about them is in no way saying they are bad or anything, just pointing out a few couple could be errors to try and help you out as a sprite, not saying you need the help though. I apologize for the length, I hope it's not too long/short.
Monumount- Well one thing I noticed was the blue and green pixels. I want to say the green was on purpose most likely, but on the bottom right you have some blue stray pixels on the border. On the subject of borders, you have two different kind. One seems to be left over from Geodude's colors. The slab coming form the top of its head seem miscolored/out of place. Yet I have a hunch it's suppose to be that way. As for the colors though on it, I'm confused as to what it is. Is it like an eye, if so, then what of the things on the body that look like eyes?
The hand/claws are weird, one reason being that they are the same, just flipped around. Altering the borders/changing up the shading would be nice. Copy/flip is nice, but creates a few flaws. The feet also seem to have been done similarly, and their shading is off too. At the bottom of the feet, the shape doesn't seem right, and a hole or two in the borders.
Selion- I think this guy is cute and is a cool idea. Ground and electric is an awesome type combo, and your guys is cute. One problem I find though is that the head isn't very round, pretty bumpy looking. I'm not sure though if that is on purpose or not though. The shading is off on it though for sure. As implied by the rocks, the light source comes from the the top left, like most Pokemon sprites. The shading on your body though is coming from the bottom left. Should be light on the top, darker around the bottom. The borders shade should also be more matching to that, the light border where the light hits it, the top left, and black where it doesn't directly shine or is blocked off, bottom right. Also the metal piece on the head has purple borders, seems kind of off. Either a dark gray, or perhaps a outline of that light blue lightning I think could work nicely on it.
Psyquake - Well one issue I with him is the name, although an awesome name, it implies he is psychic, and not electric. I don't exactly get what the shading on the metal is suppose to be. It's a weird style and I don't get what it's suppose to look like. To me it just looks kind of messy, but that could just be that I'm not use to that style, it isn't really a type that you would see on a Pokemon sprite. I think its cool you're starting to incorporate a good amount of scratching though.
One issue with this guy also is an issue I have a lot, although you didn't do as bad as I have
. This guy seems to change a tad too little. Sure his lightning rod thing gets huge, but he himself just gets a little bigger and gain menacing eyes. The shading improved, but the way he is facing is off now. It's kind of just a rule of Pokemon sprites, and a good number of other sprites, that the sprite never faces the user. Usually Pokemon have them face to the left. Although to fix that issue, you just need to move the eyes to the left a bit
.
Copion - This guy has a few of your past flaws. Some green colored borders, the same claws with shading issues. As for new ones, I don't think the legs and stuff match the direction of the back perfectly. In the eye, you got some transparency messed up, you can see some red in it. The shading on the left legs are also a little off. I would say at the joints/knees at the tips, it shouldn't have those dark spots. You really surprise me with what you use on these though. I wouldn't have guessed the head was from spinerak if I wasn't already looking at it assuming you got the feet from it. The dark spot on the head though shouldn't be that shape, or there at all probably, since right the the light source should be shining there.
Chelaepion - On the chest, I see some gray/blue pixels. The position of the left legs, our left, seem off. They seem too far and not attached to the body. The head also seems to be on a very weird angle. Also the use of the same legs and claws is kind of off to me, I mean they should have changed a bit after evolving, same goes for tail. A slight size or shape change could to them some good. The right claw I find a little awkward positioned too.
Well that's all I have to say really. I just kind of picked your more recent ones. I mean if there were any specific you would want some critique on, I could probably eventually find time to do so, that is if you want me too. I in no way meant any of this to sound offensive or anything, just trying to help out. Well good luck with your future endeavors, I hope I was able to help out, even if only a little.