Law got some information that's very valuable. As knowing who are you going against before a battle could change the entire tide of battle. Because it could help them provide some countermeasure against the Upper Ranks.

He is thinking of sharing the information with the Voyagers and also the Hashiras so they could discuss what to do with it. On second thought, maybe it's better to exclude the Hashiras from it as it may arouse suspicion. Well, where the hell do you even get an information about Upper Ranks. Google? Yeah, sure.

Law is definitely sure that telling the Hashiras about a demon living on their basement is a really bad idea. So, he could count on themselves with the information. It's a no go to tell the Hashiras about this. All of them had already bad impression towards some of the Hashiras. Let's not making it even worse. He thought to himself.

Although the intel are lacking to a certain degree, the information is solid as they could get. Such as Upper Rank's Demon Blood Art  such as Upper Rank One, Kokushibou and Douma the Upper Rank Two. From what he heard, it's not like they'll show their Demon Blood Art like it was some show.

Hantengu the Upper Four is said that he could split himself once he's decapitated. Each clone of him has different abilities, but the more that he gets cloned, the weaker each clones get. The clones have a carving on their tongue.  Unless you find his real body, there's no way in hell that he could be defeated. 

Gyokko is described by Gyutaro and his little sister Daki as borderline bizarre. Even Gyutaro is sure that Gyokko is much uglier than him and he seems to believe in that. Law sure that this Gyokko guy is uglier if the ugly demon said it himself.

Gyokko on the other hand is obsessed with his own twisted way of art. His Demon Blood Art is consisted within his vase that he created. He could create lifeforms out of his vase that responds to his command.  

Then there's Akaza of the Upper Rank Three. Law didn't pay much attention about it. He already knew some of Akaza's attacks as it was told by Doflamingo before. A ferocious melee-fighter and martial artist with destructive blows enough to make a donut for a whole pastry shop. 

Although there's nothing that he could find out about Kokushibo. Other than he's a swordsman and a loyal demon towards the Muzan. His origins are unknown, but he is the first out of Twelve Kizuki. He used to be a demon slayer. 

If he used to be a demon slayer just like the Hashiras, he might have mastered a breathing technique too. Law speculated. That might be the problem.

Lastly, there's Douma the Upper Rank Two. Gyutaro said that Douma is an odd fellow amongst them. He only eats women and acts nonchalantly. Out of all demons, he's the only one who doesn't have any fear towards Muzan. Gyutaro suspects that he might uses paper fan as a weapon. As he always took it anywhere.

Law left the basement with a notebook filled with notes and information that he could get from the former Upper Rank Six. He got quite the information, but some were also left without any answer. There are limits to what the siblings knew about the Upper Ranks. They're not too close with other Upper Ranks. 

"Hey! This isn't in the deal! I've told you what I know! Let both of us go!" Gyutaro is enraged at Law for not holding the end of his deal.

"I say I might let you out. I didn't say I will, let you out." Law bids the siblings goodbye. 

"Hey!!" Gyutaro shouted. Law goes up the stairs.

*Creak*

"Hey!!" Law ignored Gyutaro and shut the door, leaving them in complete darkness yet again.

"I've told you before! Don't trust that fucker!! And yet what you've go and did?! You useless brother!! I hate you!" Daki expresses her hate for her brother.

"Shut up!! At least I tried to find a way out of here! What do you even contribute?! You good for nothing sister!" Gyutaro argues back, defended his mistake. At least he tried to find a way and negotiate unlike her sister. They argues back and forth again....

After A While...

"Fuck you!" Daki insulted her brother.

"No, fuck you!!" Gyutaro replied.

*Creak...*

"Can you guys shut up? It's annoying and I can't sleep!!" Law opens the door to the basement and shouted at both of them to stop arguing. He can't sleep because of all the noise. Law went back to the basement.

Law returned back to the basement, with a candle to see through the dark cold basement. He goes down the stairs, with a displeased look on his face. It's been 30 minutes since the siblings are arguing. 

Law sighed. He can't even sleep because of the siblings. He wondered how Brook could stays asleep like a log. It's only both of them in the estate excluding the siblings in the basement. He goes near their cells.

"Look at you two. Still got enough energy to bicker with each other so it seems." Law interrupts the siblings.

"Shut up! Don't butt in! This is a family matter!!" Daki shouted at Law. She's still have a lot of energy after all of that cursing back and forth relentlessly.

"What do you want from us? Take note that I won't tell a single shit." Gyutaro won't get tricked twice. Gyutaro was about to say more, but he stops when he sees a large wooden box. he started to get curious.

From his pocket, there's a few candles . He lighted all of them and put in all across the basement. He put the wooden box aside. 

"You've given me quite the intel. I've thought about it again." Law tells him honestly. Thinking back, he would like to do that and be done with this, but he can't just yet do that.

"I can't let both of you go yet." Law brings them the bad news.

"Great...we'll be stuck here again." Daki rolled her eyes. She gritted her teeth. She really hates being here. Everything sucks here to be fair.

"What do you mean by that?" Gyutaro breath a sigh of relief but he also didn't understand why Law can't just let them go. Well, not letting them go but at least confine them in much better place.

"I can't make a decision without other's approval. There's also other problems, but I'm too lazy to explain it." Law can't make a decision by himself. He needs to consult other's opinion.

"Like what problems?" Gyutaro would like to know more.

"First of all, you both are technically excommunicated by Muzan. You've lost to us. That's pretty much makes you worthless in his eye." That is the fact that Gyutaro can't deny. Muzan hated incompetent subordinate.

"Even if you went back at him, he's probably going to kill you and replace you with other demon. Muzan is not going to give you a second chance." Law continued.

"That's not true. Muzan-sama appreciate me more than other Upper Ranks!" Daki defended Muzan and believe that Muzan won't do that to her.

"Ume, stop..." Gyutaro called his little sister by her real name.

"What?!" Daki can't just believe how easily her brother got swayed by couple words. She is still loyal as ever to Muzan.

"He's not going to welcome us and let our mistakes went by." Gyutaro understand what Law is trying to say and reach out to him. 

"Then even if I granted you your freedom, what are you going to do? You're basically deemed as useless by Muzan and also the enemy of demon slayers." Law makes a good point. There's nothing left that they could do.

"Stay here for a while. I'll add some things that'll make this shit hole at least bearable to you fucks." Gyutaro and Daki are left silenced as the doctor got back to upstairs.

Gyutaro is left with a hard question.