I still have lingering issues from my abusive ex friend but can't admit it
That sounds very concerning, what did they do?
I had to cut him out of my life. He insulted and psychologically abused me and my friends and was an overall negative influence.
They should never have treated others that way. Being abusive towards other people will hurt others and make others dislike them.
And to emphasize, they wouldn't change.
Oh, I'm so sorry for you and how your friend treated you. If he can't change, then I think it's healthier for you to drop the friendship overall. If enough of his friends end relationships with him, then there may be a chance he may self-internalize about how he treats people and possibly change for the better.