Good piece, has a charming style to it and a well execution of emotion on simple figures; Although the composition could be a bit better, currently it feels to dull and doesn't do the rim lighting or well the lighting in general justice. I slightly altered the piece and colors to give an example of how I would do the lighting https://i.imgur.com/tCusV1H.jpg Hope ya don't mind

The quality of this artwork is great, good gesture and neat colors, although I feel like you strayed away from the original character design too much, Take away the ear piece and it won't resemble as D.va anymore. In my opinion I feel like you could have executed the character design in your style a lot better.