So, a very common fanfiction thing is to take dark/black magic and turn it into basically just any type of magic. Just a flavor/personal preference. But that misses the entire point of dark magic existing. I understand why folks do it, it's because they want to show "shades of grey" and also because the gameification of fantasy has made the dark side just the same as the light but with melodrama and black cloaks. But that makes characters so much less interesting despite what some think. Because the concept that folks shrug off their morality to gain power is interesting.

The concept of a power that corrupts those in contact is interesting. Especially when paired with folks with good intentions. By flattening it, you might as well not have it. Oh dark magic is just regular magic but it hurts a little or requires blood? Everyone would use. Literally everyone. Evil exists both in fantasy and honestly the real world too. Trying to, shades of grey away evil is boring, and also gets problematic real quick when ya know, the evil is a Nazi/Klan analog. Instead you could ya know, show redemption, show how folks originally maybe weren't even that bad before they got corrupted.

Maybe someone like Lucuis Malfoy was originally like, a very low level bigot. Not good by any means, but also not trying to hurt muggleborns. But being tempted by Voldemort and diving into dark magic changed him. Snape is another great person to show with this. We know from year 1 he wanted to learn dark magic. It's part of why James hated him right off the bat(plus childish crush on Lily). Maybe show how dark magic ruined Snapes life, how maybe it is responsible for some of his worst moments even today, as he is connected to it via the mark. Heck, show someone like Hermoine using it for pure intentions, carefully, and still get really screwed over by it.