Edit: Wrong thread @_@
Is this another piece you are looking for critique on?
There's not too much to critique from my point of view (Aside from the infused Asriel pic) as your drawings are very heavily stylized.
I can't help but notice however that your art style changes a fair bit from Asriel to Chara. I'm not really saying you may have not drawn these entirely, but in the off chance that you did I don't really recommend selling them. If you did however, then I'm totally sorry and feel free to sell some art.
I love the different line thicknesses on the Chara picture! Varying how thick your lines are throughout a picture is a great way to add some oomph to your drawing.