So, a couple years back I had a terrible manager. He was a nepotism hire, and didn't even have a degree, let alone one related to the technical department he managed.

I unwittingly made management look like a joke with my projects and studies, and he took it personally. He made my life a living hell, and set me up to fail, and fired me.

Now, years later, employers are calling him up and he's badmouthing me so I got ghosted for a second round interview!

Fuck this stupid fucking chud of a man. He made my life so bad I considered checking out of life, left me unemployed for half a year, and I got saddled with 10s of thousands of dollars of debt from said unemployment.

Should I warn employers of this bad egg? "Hey if you contact this employer, my direct manager had personal grievances with me"

Or do I just say nothing since that warning would cause hiring managers to skip over me?