The truth is, I don't know. I only know what was told to me and what I've learned since coming here.

What I do know is that the type of Noise this person - and anyone who learns of it from him - can summon are much stronger than normal Noise. Fighting the person themselves would be even more difficult, because they themselves became this type of Noise.

I doubt it's impossible to stop him if he were found, but...I do know that the only person who seriously injured him during the Incident was the Composer of Shibuya. And he's likely gotten stronger since then.