He is starting to threaten doxxing now.
He also cropped out his alt account from his original screenshot.
Additionally I appear to have blocked the god destroyer at least 330 days ago.
I'd send that straight to Itch.io via the Email link they provide in support. Be sure to screenshot/document all of this. I'm sure he's probably running a VPN/TOR combo, and thinks he's untouchable for it, but Itch can still ban the accounts and blackball the associated email accounts. He claims he's not from "my country", but considering he couldn't know where I possibly am with my own VPN/TOR combo, the doxxing thing seems like more of a bluff than anything else... trying to scare you into-- what, exactly? It's all so random and pointless.
As for the cropping: he's posted that screen shot so many times, it's laughable, and I promise you at least one of them will still have his name on it. Even so, I have a screen shot of it already, so he can't really deny it, even with the altered image.
Let him keep digging his own hole.
Dissecting that image: there is nothing even remotely resembling 'evidence' in it, aside from his own alt profile posting the link to whatever nastiness is there. The snips are altered (one is clearly enlarged) posted out of order (you can tell from the reply lines) and there is absolutely no reference to which discord server(s) they were taken from... without the entire, unbroken, and unaltered conversation this is nothing more than a collection of out-of-context snips, possibly from multiple conversations and multiple Discord servers, served up in a mosaic. No logs, not even screen shots. The only individuals represented in that pic that could possibly be associated to each other are the ones responding to one another, and there is no possible way to solidly associate those individuals with anyone on Itch.io, because as far as I know there is no way to link a Discord account to Itch.io like you can with other media accounts. In no world is anything in that image even moderately convincing 'evidence' of any kind-- it only demonstrates a wholly unhealthy obsession on the part of the person posting it, and a malicious intent to damage the reputation/image of anyone they perceive as an adversary. Ordinarily, something like this is cobbled together to look at least a little convincing... this picture is just a disjointed mess.