Lineart: Clean, well done
Eyes: Amazing and simple
Poses: Original, they fit the characters
Shading: Between simple and complex
Background: Basic, good techniques

Lineart
It can be difficult to say much about lineart, unless it's absolutely terrible... this came out well, it has clean, thin lines.

Eyes
Another category it can be difficult to critique, in all honesty. But, since there are three characters, it's easier... I'll critique them now. Haha.
They all look gorgeous, you used different styles in all three of them. The eye patch detail is good as well.

Poses
I must say, Meg looks very simple, innocent. I'll bet she's not so much... anyway, the proportions look real, good job. Her wings look awesome; how do you draw them so well? Echo has a sort of badass appeal to her, and she seems to remind me of Terra for some reason. Lavvi's goofy expression leads me to believe that she's the leader of the group, even though she's possibly the most, uh, immature? That's not the word I want to use, maybe fun? Hehe.

Shading
You do some decent soft shading, Tess. The pants on Lavvi look great, almost like something from an anime. The little highlights on Echo's wings look great, keep up! Everything looks natural, there's nothing that looks off to me.

Background
Your background is short, sweet, and to the point, as is my critique of it: It makes the characters stand out. It makes things look awesome.

Never give up, let your dreams fly~

It's hard to believe these three are evil with the expressions you've given them. Cute, Sexy, or maybe even a little dorky but not evil.
One of the things that really sets this particular piece of is that you have this lines going down to the characters, literally drawing our eyes into the characters instead of having our vision float around them. These splatter designs in the background also set it off in a way that makes me think, "what is that? what does it mean?" It also helps pop the vision back to the foreground with the blue lines.
All in all I'd have to say this really works with what you have going on here and it is a pleasant stray from your normal style. Well done.