What would you have me do? Just shut this all down?
Of course, don't shut it down! Just shut him down.
I understand that you want to be tolerant, and that you want accommodate anyone or their point of view - that's very laudable. If he wants to post nonsense, fine, let other people either ignore it or contradict it. I get that he may even seem a good foil for some of us and that you might get a kick out of it.
But you can't permit him to, effectively, set the agenda. I know this is not what you are thinking, but it appears that you are willing to let Charles make unilateral decisions about the value of everyone else's contributions. It looks like that you are favoring him and accommodating him to an extreme degree, over the rest of us. No matter what he does, there are no real consequences, while the rest of us not only just have to have our contributions wiped out in one of his predictable fits of pique, if we complain about it or ask for action, we are the problem and get yelled at, not him.
Don't forget that the basic problem is that he intentionally causes havoc - not that everyone got upset with him for it.
You may think you can reason with him, but I seriously doubt it. He has no idea why everybody is upset with him. I mean, look at the responses he has written to this, they are utterly delusional. He sees the issue as everybody acting strangely while he is the one sane man, and that it is his job to keep the discussion flowing in the direction he wants it to flow.
Making him a mod of his own forum convinced him that he is part of the site management, so he probably thinks he is just keeping a lid on "his" site.
If you just remove his mod privileges, he will have to ramp up his nonsense posts elsewhere to get attention, and then he will inundate you with takedown requests as other people respond in a way he does not like or approve of - which will be nearly all of them. It's perfectly clear that even now, after deleting other people's posts yet again, and causing havoc for more than a year, and listening to whatever you have told him off-line he still considers himself the innocent victim of a bunch of bullies instead of the wrecking ball that he has been.
Everybody, including you, have been putting up with this for a few years now. I think we all understand that this is your forum and you can certainly decide how you want to run it. But you can't let Charles wreck it for everyone else, and he definitely is not learning his lesson.
Brett