Both accounts heavily use ellipses (...)
Both accounts heavily use the word "just" in similar ways: "just trying to," "I just thought," "just because".
Both accounts typically use long compound sentences and a pretty high level of vocabulary.
Both accounts sometimes lapse into using improper words like "cuz," "ain't" and "gotta."
Both accounts have similar behavioral patterns of defending their own ideas and attacking other people's ideas.
Oh crap, I do all these things, too! The real ErrinF was me all along! Well, depending on your definition of "attacking", and on how "heavily" the ellipses use is
Actually, no, you don't!
To really get a feel for it, you need to go through and carefully read the accounts: ErrinF, ErrinFU, Horatio83, Tristan. I believe there were a few other smaller ones as well. They have a distinctive writing style and distinctive argument patterns and distinctive shared interests (fan cards and getting in arguments).
Your writing style is nothing like it and it is easy to tell the two apart. If you want to know how heavy the use of ellipses is, go look for yourself. It is actually quite extreme.
Why it wasn't so long ago that I falsely accused the horatio83 on these forums as being the same horatio83 that played on Goko, and my wasn't that embarrassing for me.
So what you're saying is that this person--who is known for telling lies and avoiding responsibility in order to make other people look foolish--told you: "That Horatio83 and myself are two completely different people," and you believed him? and now I'm the foolish one?
Look, I'm not saying I am 100% correct here. But honestly the biggest behavioral patterns are the ones that are most awkward to talk about because they are the one that boil down to "turns into a troll when people say his fan cards are bad." That's the one major thing that all of these accounts have in common.
Anyway, Awaclus has it right, it's not worth putting more effort into proving, it's just something interesting to speculate about, and there's nothing else on here particularly interesting to me right now.