First Impressions: Cool, anime, supporting character
=I think it's a pretty good design; I especially like the high-contrast shading on the tattoos (first pic); makes it look like they're metallic.
The only thing I would change is the blue vest-thing...it doesn't add much to the outfit (at first I didn't even notice it, until I looked at the second pic and went "what is that big blue blob") and it seems like it 'dampens' the dynamic of the overall design, both in color and silhouette.
If you want to keep the color, you could add it to his hair, or give him a belt. If you want to keep the 'element placement' (Idk how to explain it) you could give him a backpack, so the blue bands over his shoulders remain, but stop there.
First Impressions: Plain, innocent, ordinary
=The design looks pretty simple, but not too simple compared to those of the other characters.
I think you accomplished this. The big black buttons and the unusual skirt shape give off a subtle 'clowny' vibe, but just enough for the outfit to still look like something the average girl might wear.
First Impressions: Cute, dangerous, cool
=She does look cute, but I don't know if she looks 'particularly' cute compared to the other characters. To be honest, the fringe over her eye and the earrings give her a kind of 'bad girl' vibe that probably warns the reader ahead of time that she may not be harmless.
I think so. She definitely has that factor...I just hope you won't be disappointed if people aren't 'fooled' or surprised when she does something violent. Like, IMO she's less of a 'cutie who you'd never suspect would be a murderer' and more of a 'cutie who is a murderer and fulfills both roles flawlessly'.
Hmm...a fox, I guess. A fennec fox, specifically, due to her coloration. ^^