"Joy Boy?"
"Yes, and that Joy Boy seems to be Luffy. I think the real owner of this place was Joy Boy from 800 years ago. But Joy Boy seems to be a title given to someone who comes from a certain lineage and has a certain power that will carry the things in prophesies written in poneglyphs. Based on what Kaido & Zunesha said, that person seems to be Luffy. These robots also explained Joy Boy's characteristics and all of them matched Luffy, especially his power after he awakened his devil fruit."
"Hmm, then maybe we can try to see if Luffy can really inherit this place."
"I also intend to do that, but I don't know where Luffy is."
"Hmm, I can take you there. Let's go."
Jon teleports them all to Luffy's location. Luffy is in a room that looks like a dining hall with Usopp. They are being surrounded by more robots than Jon, Jane, Brook, & Robin. Though it seems to be caused by Luffy who broke some robots which made the robots called reinforcement.
"WAIT! STOP FIGHTING! THIS PERSON COULD BE THE ONE YOU ARE LOOKING FOR! THE NEXT OWNER OF THIS FACILITY."
Robin shouts to the robots while Jon is pulling Luffy & Usopp into his skeletal susanoo. Luffy and Usopp have some injuries caused by the robots' attacks. Their anti-devil fruit users' bullets seem quite effective to even deal with Luffy.
"Their attacks could hurt you, huh?"
"Yeah, their bullets were so strange. After they stopped attacking for a moment, their bullets suddenly could hurt me. I tried protecting my body with haki, but their bullets still hurt me. Usopp said those bullets were mixed with seastone. So I've been dodging their bullets while trying to attack them back. But I need to protect Usopp sometimes, so I took some bullets."
Jon heals Luffy with medical jutsu while Robin tries to talk with the robots. These robots have just received reports from the robots that surrounded Robin & Brook about the possibility of Luffy being their new owner, so they aren't attacking again.
While treating Luffy, Jon sends his clones to check their crewmates. The clones teleport to the other locations and the situations are mostly the same. Luckily they all are fine because it hasn't been that long since the robots attacked them and each group has at least 1 good fighter.
Jon's clones teleport everyone to the dining hall. More robots have come there and then another robot that looks like a cat mink with a maid outfit enters the room. If not for its lack of chakra and presence, Jon would think that this is a real mink because it looks so alive.
[Please follow me. We will do a test to check if you are qualified to be the new owner.]
The cat mink maid doesn't say much and just leads them to do a test. They follow her to another room located quite deep inside. The room to do the test is a laboratory with many tools and machines.
There is a small reindeer mink robot that looks similar to Chopper wearing a lab jacket in the room. But this reindeer mink robot has white mustache & beard to look like an old scientist. Also, it doesn't have horns, and its nose is black.
[Who is the one who will take the test?]
[It is this person.]
The cat mink maid points at Luffy and the reindeer mink scientist approaches Luffy. It raises its right hand and suddenly a syringe pops out of its index finger. Then it asks Luffy to show his hand before taking some of Luffy's blood with the syringe.
After that, the small reindeer mink drops Luffy's blood into a bigger tube filled with a blue liquid solution. The blue liquid becomes purple and then red after the blood is dropped. Then words and numbers start appearing on the big screen to show the reading.
"Can you really check everything just with blood?"
[Genetics will still remain even after hundreds or thousands of years. It will be diluted a lot after many generations, but some genetic traits won't disappear. This machine can extract genetics from the blood and compare them with our data that the owner left to their details.]
"Damn. Can't believe this is a technology from more than 800 years ago. Just how much of their knowledge has been lost after they disappear?"
"I wonder how great today's technology would be if no knowledge was lost and we kept advancing."
"Well, at the very least there won't be those idiot Celestial Dragons because they didn't win the war 800 years ago."
"Those Celestial Dragons were the biggest problem in this world."
Soon, the reading of Luffy's blood sample is done and every indicator is green. As soon as the result comes out, all the robots look at Luffy and kneel. Everyone is stunned. They don't need to ask to know why these robots act like this.
"W-what's this?"
"Congratulation, Luffy. You have become the boss here."
"Hey, is that really the only test?"
[Yes. We can get a lot of information just from blood, especially lineage and power.]
"I can understand about lineage, but what about power?"
[As one grows stronger, their genetics also change. Their power is being imprinted in their genetics and can be passed down to their descendants. That is one of the reasons why powerful people usually have powerful descendants. Then just like personal power, devil fruit abilities also have effects on genetics.]
"Even devil fruits?"
[Yes. Upon consumption, devil fruits merged with the users' bodies to genetic level to affect their whole bodies. The longer and better someone is using their devil fruits, the bigger the effect is on their genetics. It will be especially strong if the users manage to awaken their devil fruits, just like the new owner.]
"Oh, that's why a blood test was enough."
[Yes. We have confirmed that Master Luffy has the blood and even the power of our previous King.]
"Hmm? Not just blood but power too."
[His devil fruit is the same as our King. Our King once said that someone with the same blood and power as him will come. He told us to serve this person just like him.]
"How could he know such a thing?"
[Someone very close to him has the power to see the future. Together, they record the future that person prophesied on special cubes and spread them all over the world to guide the people in prophecy.]
"Does that mean our arrival here has been prophesied too?"
[We believe so.]
"Um, Professor Robot, is there any complete record about this prophecy? I would like to read it because I am the only one who can read the words on those cubes among us here."
[The complete record is written on this building.]
"It's not written on something smaller like books?"
[We were prohibited to make copies of the record that was written on the cubes. If you wish to read the record on this cube, then we can provide an assistant to help you read the parts that are in high locations.]
"Really? Thank you so much."
"Hmm? Now that I think about it, how can we talk with the same language? I thought the Ancient Kingdom has a different language because they use a different writing by seeing the poneglyphs."
[We were using the same language as the whole world. What is written on the cubes are symbols only the Royal Family and their close aides know. They used these symbols to prevent the enemies from reading the record.]
"So it's like that."
After Luffy is acknowledged as this facility's new owner, they start exploring this building. Now they are free to go anywhere they want without being attacked by the robots. The robots even guide them to the rooms now.