The Ancient Kingdom was a kingdom said to be enormous, prosperous, and powerful. Its true name is still a mystery, as Professor Clover was executed before he could speak its name. Why is this name so dangerous?
The Ancient Kingdom had a name that in the current time of One Piece would be so dangerous that saying this is enough to immediately execute someone who was already theoretically going to be executed, but would serve as a source of information beforehand.
Maybe Imu was in the room at the time and would throw a tantrum if he/she heard the name, but I think it’s more about not letting even elite government agents hear it. What word would be so powerful?
It’s not about power, it’s because if you were born in the world of One Piece, at some point you’ve heard the name of the Ancient Kingdom.
In my opinion, there is only one reason: this kingdom still exists. The government doesn’t want anyone to start any kind of thing that could cause a conflict, which they don’t want until they are sure of victory. The kingdom is quiet, waiting for something, or perhaps this is also a secret that is only passed on by their royalty. The World government even managed to finally recruit members of the race that forms this kingdom.
I believe it’s Elbaf, but Elbaf is not the whole Ancient Kingdom, it’s only a part. The World government defeated the Ancient Kingdom, but they were unable to completely erase the Ancient Kingdom, Elbaf being the remaining part of it.
The World government wants to completely erase the Ancient Kingdom, so they performed experiments to turn their warriors into giants. And Shanks, the supposed pacifist, chose Elbaf as his territory to delay this war. He is an asset to Elbaf should any conflict arise. And this position gives him the possibility of talking to the Gorosei.
Also, the giant robot on Egghead was just a ‘regular’ robot to the people who invented it, like Ancient Weapons being ‘regular-sized’ for giants.
