I experienced him crash a server I was on. I recorded his ID and took pictures and saved them as evidence.
He threatened for the host, 255, to give him admin or else he would lag/DOS the server.
Here's screenshots I took after the server crashed because the chat was still saved.
Yes, it was an Undertale freebuild server, that's why 255 banned him with that reason.
And then I took
a screenshot of his names when I did an ID lookup. This was yesterday.