Wondering if this is personal grudge
Definitely a personal grudge. It was against someone who the downvoter was convinced is an alt of mine (it's not).
Several months ago, I mentioned how weird it was for someone to have an ai girlfriend in general, not calling anyone out directly. One particular dude stalked me for months over that comment, and serial downvoted everything I did.
Then he put his sights on someone else (the subject of the scenario in OP's example), wrongly thinking it was me, and started stalking and harassing them, and calling them my name. Literally saying, "I know you're Universal Monk!" Over and over. Again, the person he thought was an alt of me, isn't me. I don't have any alt names. I just use my Universal Monk name on any instance I use.
As soon as it was mentioned that the serial downvoter guy may be involved in sending the Nicole fediverse chick spam (many of the same addys, obsession, etc), the downvoter deleted his account.
I have no idea if he was involved in the nicole spam, but the M.O. of revenge and obsession definitely fit the profile for both the incidents. Also pretty suspicious that the minute someone mentioned he may be involved in Nicole spam, he bailed and deleted his main account and a lot of his alt accounts. lol
What’s also funny is that now that people are finally talking about “serial downvoters” being a problem—and now that more users can actually see who’s doing the downvoting—a lot of those serial downvoters have suddenly stopped.
Personally, I’ve noticed a huge difference. For a long time, it didn’t matter what I posted—no matter the subject, I’d get flooded with downvotes almost instantly. That’s just stopped.
Now the voting feels way more natural and organic—based on content, not just someone hating me and hitting downvote the second they see my name.