I don't think this is actually a difficult problem. Some simple machine learning on word frequencies, bigram frequencies, etc. will be probably enough to solve it.
Friend of mine did it via computational complexity: using gzip (as an approximation for KC) for attributing classical latin literature to their respective authors by checking which strings add the least additional complexity (due to shared writing styles, word choice, etc.) when compressed together and then clustering. Worked like a charm.
ETA: These were large bodies of text, however. Probably not gonna work for a bundle of comments, except for me, due to my overuse of "obviously", obviously.
I know this reeks of witch-hunting, but... I have a hunch that u/Eugine_Nier is back under the guise of u/Azathoth123. Reasons:
I don't have an axe to grind against the guy, I've only spoken to him a couple of times and didn't notice any particularly large karma hits afterwards, I just really dislike it when someone skirts the rules like that. Disruptive users evading permanent bans never helped any community ever.
Obviously I'm posting this here because I think a moderator should look into the matter. Usually I would be posting a disclaimer of some sort, apologizing in advance to Azathoth123 for attacking his standing with slanderous accusations if this turned out not to be the case. Well, I won't. The more I look into the matter, the more confident I get that they're the same person. Azathoth, if you're reading this and you're not Eugine_Nier, then I strongly advise you go search for your twin brother, I think you'll get along very well. Seriously, I'm saying this in good faith. You have a suspiciously great deal of things in common.
If retributive downvoting is (still) a concern (if not, then disregard this paragraph): I'd like to request, if such a thing is possible, that a mod karma-blocks me until the issue is over, so as to not incur undeserved downvotes (it would also mean I'd get no upvotes). In turn, I promise not to abuse the system by spamming the boards with garbage without consequences, but then again given my history so far on LW I don't think that such an abuse should be expected from me. For the record, I could have made a throwaway account just to say this, and not risk being karmassassinated, but 1) a zero karma account has no credibility and 2) for signalling reasons I prefer to put my money where my mouth is.
P.S. I only made this announcement its own post because the latest open thread was about to "expire".