You know, I've seen Tapion and Cell, but can't remember your Yamcha
First off, the SF3 based edits just don't do.
They look out of portion and your spriting style looks too distinct from SF3.
Your own style looks unique.
Broli:
- Bad proportioning from SF3 bases.
- Broli's body clashes with the rest of the sprite.
- Folds on that skirt-thing looks flat, give it more shape.
- Boots look out of shape, they should be pointed
Your Yamcha looks great ;D
Yamcha:
- Pants look too plain, add some details like folds.
- His legs looks weirdly shaped, could be the proportions like placing the knee too low.
Cell actually looks good, but the proportions from SF3 are horrible
Cell:
- Shoulders seems way too wide for Cell
- Body looks a tad weird and is also too wide
- Legs are too wide.
- Cell's feet should be pointy, you made them look round.
Overall impression of Tapion is good.
Tapion:
- Some of his hair might get a tad longer and messier for more accuracy, looks good though.
- Ear could be longer too.
- Blue-shirt-thing on the bottom could get more shape.
- Orange-back could use a darker tone to give the impression of actually being behind.
- The orange-back and blue-front look flat, possible caused by the lack of details, shade and shape.
- Sword doesn't look accurate.
- Sword looks lik it's edged on 1 side, because the point looks like a saber/katana.
You might want to practice on editing feet and shoes and work on shaping.
To me it looks like you first determine the area you want to cover and then fill the shape in with shades and lines.
Try to give the figures more shape and depth!
That's it for now, hope it's useful to you!