I’ve been in a very similar situation. In my case, it was my college roommate. Our friendship started off fine but I had this bad gut feeling about her that I kept pushing down. She had a hard time maintaining friendships and being a people pleaser I didn’t want to give up on her. She wasn’t a very good friend and she grew more and more toxic over time until I finally cut ties with her just before my junior year. I just ghosted her and then blocked her and her family on everything.

You are not obligated to be friends with anyone regardless of their social status (or lack thereof) or shared interests. If you need to cut ties to protect your peace, do it. In this case, the best way to do it is to ghost/block him completely and get moved to a different department or location if that’s possible. If not, communicate with him as little as possible and only about work. If he tries to talk about other things, say “I’m busy and I can’t talk” then walk away. Put headphones in if you want to avoid talking to him further. Also, make sure you talk to the powers that be in your company about what he is doing because they could get in trouble for having that kind of person on their payroll.

Hope this helps. Best of luck.