So...
The guy that's been deleting posts all along is macrocylce, the same guy who wrote Star-Lord.
He has deleted every single post of his in the thread,
including the sign-up, so if you go to page 3/4 or whatever, you'll see his name on the list, but the post of him signing up is nowhere to be found. I have no idea why he did it gradually and not all at once.
He admitted it via PM and said his reason for doing it is that he wants to completely erase his online presence. Then, I asked him why he was so passionate about participating in the comeback round (he expressed his excitement for an invitation via PM and inside the thread) and he said he didn't think he'd get invited since he didn't do well in the first round anyway (which is true

)
Yesterday, when I told conatus to PM me who he thought was deleting posts, macrocycle was the second name he guessed and I told him he's wrong... I did NOT see it coming...