Similar to Stross' Accelerando (a book released just after the Napster era), where russian mafia legal bots went around suing everyone for whatever reason they could get their hands on.
Ironically, people doing this en masse would probably force some attention from those with power and might cause the scales to be a little more balanced. One can dream I guess.
You don't even need a company, just pretending that you represent one is enough.
The DMCA completely ignores how the digital world works; it was written in an age where interacting with the American legal system required you to have somebody physically located in the US.
Back then, you didn't need any technical safeguards against this kind of abuse. As long as such abuse was illegal, and there was police to arrest those committing the crimes, it was enough. In technical terms, the security was implemented on a completely different layer of the stack.
This is no longer the world we live in. There's nothing stopping somebody from e.g. Russia from pretending they're a relevant copyright agent, and forcing Youtube to remove anti-Putin videos.
Funny thing is it didn't have to be Funko or Brain Shield, anyone could have impersonated them in a takedown notice, it could have been a way more bogus notice too by the looks of it.
It's definitely the registrar who's at fault here.