I just heard someone say something along the lines of "you're evil but deny it because an evil person never realises they're evil"

Yeah but whoever says it first wins

This is deep!

Smart thinking and right on. The best determiner of guilt, is the always pointing fingers and blame at others. Projection. It's always a biased opinion, so most times it's moot

its the narcissism😈

What's the context of this? Or did you overhear a random convo?

One of the many reasons why people should stop using the argument that the other person is "evil", or engaging in some sort of ism, phobia or any other sort of ill intent. It's subjective, is not an argument and intentionally distorts the discussion. There was a time when things were "leave your feelings, your identity etc at the door and just bring facts and let the best argument speak for itself".