Some of the AA is turning into banding.

Damn great art ;3 I wish I could do something similar to this one ;D. Looking forward for next arts ;3

oh wow thanks so much for taking the time to comment & critique!! i see what you mean. i did have a feeling that the piece needed a little more working, and i'll get around to fixing it sometime.

Aw yiss purple ladies <3

I was going to comment about how this could use some AA, but then zoomed in and noticed you do have AA! Your shadow purple is too dark to be effective AA, as it's too similar to the "black". The light purple makes a better AA colour for this, in my opinion.

...and then I got carried away making a possibly over-AAed edit instead of doing my own work. I hope it helps, if not for this piece, then for the future! Long line segments need long AA. It's alright to have your AA take up more than half the length of the segment you're smoothing, sometimes.