I was on a site with some people like that.
One claimed everyone was hassling him yet he was threatening to kill - as in was going to visit them in the flesh and do it - everyone who didn't tell him what he wanted to hear on the forum. He'd make fake profiles to pester those that blocked him.
Another stalked a member on that site and on another he found her on. She deleted the other and contacted the cops since he found out her home town and threatened to come find her.
Both would be lucid at times, then go off into ever crazier babblings and scenarios.
I contacted the FBI because yet another one sounded like he was prepping to go on a shooting spree. He too had schizoid episodes.
One went crazy on me, paranoid schizo. Every little thing I said she claimed was about her, no matter how unrelated. She enlisted that first guy I mentioned to help her. Lonely and gullible and nuts, that fueled him to go after me & my friends after he had cooled down since his intro.
Like Grind, all 4 would snort farts out of bungholes, but if you disagreed with them, you must be out to get them. They'd stalk people then claim everyone was conspiring against them. They told weird stories, caused trouble, never took reponsibility for what they did, and were potentially dangerous.
That they were able to be nice when warned by the admin to do so or when they were chummy with you showed they could control themselves, so no excuses. That and and that they were infantile and caused trouble when things didn't go their way made me lose all sympathy for them.