This is the best way for you to avoid his shitposting. However, when a newbie makes a question and this beast comes spitting nonsensical FUDs that bring confusion and upheaval the thing takes another dimension. Shall you leave this unchallenged?

And what happens when there are people who will abuse it? Who will manipulate the newcomers' opinions with their dogma? Propagandizing invades my speech. Let alone to be discouraged to clear up the confusion. Freedom of speech, yeah, but moderately.

Besides, isn't he already getting his posts deleted constantly for trolling? What else do you need to ban someone by that causation?