Yeah, I'm going there.
After kid fucker Kaarous claimed the admin told them I had alts (yes, they're long dead and were used after someone spread a claim about me that was hilariously untrue...), it demonstrated something.
THE ADMIN CAN SEE WHICH ACCOUNTS ARE THE SAME PERSON
So why does this one keep coming back?
A probable answer would be if you use the same narrow IP range and the spammer uses dynamic IP and spoofing so that an IP block or checkuser is ineffective.
However, I'm not confident that you are capable of quoting u/Kaarous accurately anyway, so my idea may be irrelevant. Maybe you're just a dead giveaway on your alts.