I got my username from a book called Erebos which was written by an author from my country. At the time I was 11 years old and I was realyl getting into online games and since I've never known an alias aside from "Player 1", so I set out looking for inspiration and found it.
It sounds really cringy, but it has an intresting backstory.
So osu was kind of the first game i have began actively playing. I have started playing it when i was 6 years old, and since you can't rename yourself it stays like that.
Basically i wasn't very original and didn't think too much of it because i have wanted to quickly play, and i have just reversed my name (nikita) and put my date of birth. It sounds like a joke and like the worst username ever, but it reminds me of myself as a kid and i really like it because of that. I would have changed it, but maybe it will stay for good.
During the big Dubstep trend about 7-9 years ago, there was a very popular artist named "SKisM". His music was one of the best next to Flux Pavilion and Skrillex.
My username before that was "LoLMeCrazy" so I definitely needed a new ign, so I went with "SKiisM" since I was a huge fan of his music. Barely anyone recognizes the name since the artist phased out awhile ago too.