It’s truly heartbreaking. The guy was one of my closest friends because we had a ton of hobbies in common. I loved when he would target fixate on some problem and his basement would turn into a mad scientist workshop. I remember him as “the person who would see through a ridiculous idea.”
But the abusive parts got worse and worse and became intolerable. I’m not sure what could have been done differently. Though as a teenager that was probably not my role to play.