Usually it's best to ignore those kinds of messages. This thing is pretty common and it's usually girls (sometimes guys). they get into your DMs and try to feed you a bunch of weird shit about people that you barely know, or don't know at all. Then they start making up even more ridiculous shit to see if you actually go attack anyone.

If you play along then suddenly expose their nonsense, they get all butthurt and start tell people you're evil and make up a bunch of ridiculous shit about you.