Rui was freaking out, his domain was being invaded by demon slayers and he didn't know what to do.
He wanted to kill them all, that way they won't be able to get close enough to his family to the point of killing them, but he knows his lord won't like that, the reason for his indecission.
Ever since the change of king, the demons started eating less and less humans, but there were still some that ate them and his family was a good example for that.
He forgot to tell Muichiro if he was kind enough as to give each member of his family a drop of his blood, and it seemed that his lord forgot too.
Rui sometimes wonders if Muichiro was as forgetfull as he is now, before he was their king, an answer he will only get if he asks Muichiro himself.
But back on the main topic...
Rui as a solution to his problem, decided to ask the demon he calls mother to try to slow them down by using her blood demon art, he knows that his bda is more efficient, but since his strings are harder than her's, he isn't certain that while trying to restrain them, he won't cut by accident a limb or two.
Everything was going smothly, there was no slayer dead yet, and no member of his family was killed.
That was until three boys entered, one was a blond crybaby, another was a boy with a boar head as a mask, and the last one was a boy with burgundi hair, hanafuda earrings and he was carrying a wooden box in his back.
He could clearly feel the presence of another demon inside the box, but since he didn't wanted to invade the privacy of the slayer and he didn't wanted to be discovered by them... He decided not to mention it, and he just resumed his path of scouting the well being of his demon family.
While he was doing that, he could see that some stray demon slayers that got to his brother's place were being taken of by his brother... Meaning that they were transformed into mutant spiders.
Rui is 100% sure that he told every member of his family to not hurt any human, including the demon slayers, that place a foot in the mountain.
Something that his brother completly ignored in favor of creating more of his minions.
He wittnessed the battle his brother had with the blond crybaby, and Rui got surprised at the strength the slayer could get every time he was knocked out.
The slayer was so fast he could barely see him, so Rui made a mental note to himself, to never let that slayer get knocked out if he ever was to figth against for his brother...
He deserved that fate, if he continued to eat humans it was bound to happen, ohh, and he also dissobeyed his direct orders of not harming any human, and while he had changed his view of his family, and started to care deeply for them...
It does not mean that he will save them from a problem that they put themselves in, and if that means that he will lose a member of his family, then so be it.
He then went back to the rock where his mother was controling the slayers, he could feel that she was getting nervous, ever since those particular 3 slayers got in the mountain, the rest were able to discover the treads conecting them that were making them unable to move.
So she tried to make them drop their swords and then control them to hit each other in a presure point that will probably make them drop unconscious, it worked on some ocations, but at some point, the slayers discovered what she was trying to do and started fighting against her control, so now they were slowly overwelming her, and she knew that.
While she knew that Rui changed for the better, she was still afraid of him, fearing that dreaded punishment to come when she did something he disliked, but at this point it was just her paranoia.
Rui saw a slayers attack coming for her mother, it was the same boy with the hanafuda earrings from before, so before the slayer could decapitate her, he quickly used his strings to snatch her before the sword could touch her.
Rui quickly carried his mother to a safe zone where the slayers hasn't reached yet, he with some leaves, twigs and spider webs, made her a hidden spot that not even a hashira would think that there was a demon hidding there, he told her not to move or make any sound, something which she happily complied.
After that, Rui went back to see if he was able to save another member of his family, but he found the same slayer that almost killed his mother, the slayer was ready for any attacks he might throw his way, and while Rui didn't wanted to kill the slayer, he did felt like injuring him and leaving him out of combat for what he almost did not even an hour ago.
Rui attacked first, sending his strings at the slayer, letting them cut him before retracting them and repeating the process.
The slayer barely had enough time to dodge, not realizing that Rui didn't wanted to make serious damage, but when he tried to cut one of the strings attacking him, his sword sudently broke in half.
He widened his eyes at that, he really was not expecting that to happen, but he didn't had enough time to think about it, because more strings were heading his way, and now that his sword was broken he didn't know how he was going to defend against those.
In the end he didn't need to, because Nezuko got out of her box, and shielded Tanjiro from the attack. But it didn't hit, Rui stopped his strings just in time for them to not hurt the demoness that protected his target.
"Why are you protecting him?" -Rui asked her, he was curious about the type of relationship they had."She is my little sister" -answered Tanjiro for her, since she couldn't talk because she had the muzle on.
"Oh" -was Rui's reply.
Now he understood why that slayer became one, he had something to protect, or in this case someone.
Too bad that he joined the organization that kills the same beings that her sister became.
Before he could properly reply to the slayer, he noticed that someone was heading his way, he sidestepped to the side to dodge an attack that would have taken his head.
He could see that it was another slayer, and judging by the aura he emitted, and the slight difference in the uniform, he guessed that it was a hashira.
Rui mentally cursed his luck, and then mentally sent Muichiro his faraway, because he really doubted that he would last long enough to be saved.
The blood that he received from Muichiro did gave him strength, but it wasn't enough to battle a hashira and win... Well, maybe he could win against one that doesn't have the strength to cut his neck, it's easier to trap in his webs.
But he doubted that a hashira like that existed, and even if they did, the one in front of him was not.
He had deep ocean eyes, and a double patern haori.
Rui quickly made as much spider webs as he could to try and slow down the hashira so he could run away. It was working, but not as eficiently as he would like.
He was starting to gain terrain against him, so now Rui even started to use his strings to propel himself forwards to go faster.
Meanwhile, Muichiro heared Rui, and flashes of an early tragedy passed before his them he saw a boy similar to him laying dead in front of him, and then he imagined Rui in the same pose as the boy, his lifeless eyes staring at him.
He couldn't bear the thought of someone close to him dying again, so he ran the fastest he had in a long time to Nakime's location, and with a look that leaved no room for arguments and that promised a punishment if she dared to defy him, he told her...
"Take me to Rui's location NOW"
She complied, she knew better than to dissobey her king when he was in that state of mind, she didn't knew what caused it, but she did knew that he could handle it, whatever it was.
"With a strung of her biwa Muichiro dissapeared from the infinity fortress and appeared in the middle of mount Natagumo.
He quickly made a hood appear over him, one that covered him from head to toes, it was one of the abilities he learned he could do after he became too bored in the infinity fortress, now it was helpfull to cover himself to prevent the slayers from discovering his identity.
After making the hood, he dissapeared in a flash, running to where he could feel Rui.
He got there just in time to take Rui away from an incoming slash that would have surely taken his head if he didn't saved him.
The slayer got caught off guard by his appearance, he didn't expected for another demon to sudently appear and save the one he was about to kill.
After making sure that Rui was ok, Muichiro turned to glare at the slayer that dared to attack someone close to him, but when he recognized him, he got surprised, he didn't expected to see his father figure from the slayers so soon, he was glad the he couldn't recognize him back thanks to his hood.
So he decided to forgive him this time. He turned his back from him and dissapeared in a flash again, leaving a trail of mist behind and an astonished water hashira./p