Would FFV superboss Omega (on Final Fantasy Wiki @ FANDOM ) count for one of these? It's described in at least FFV as a "beast without a soul" roughly, and it's displayed consistently ridiculous levels of power, on top of implications that it's hunting another superboss in Shinryu.
Topic on Talk:Mechanical Abomination
I've never played FFV, but given the info on your link, it doesn't seem like more than a giant robot. Probably fits the Trope Lost Superweapon, but probably not this one.
Noted, thank you for the input. I probably won't add it then, but I wanna see if anyone else offers anything.