I dunno maybe 👀
(Just a helpful soul on the internet with 10+years experience drawing)

In regard to shading, you're literally on point for the simplicity of Hazbin in particular. If you want to improve shading, try looking at references for the type of lighting you want. light and shade can have cool or warm tones, you dont want to use pure black or white most of the time

If you would like, I have a tip about proportion; while long arms Vincent is literally so spooky and could become a part of your style, I would suggest making his upper arm shorter to at least match the other one, other than that, I suggest making his neck longer because his TV head covers it

Omgg hi I love your work and slay honestly they dont deserve u 🫶

I see I'm not the only one who saw that his antenna sparks are his emotions 🫵