*Note: I made a couple of adjustments to the original stories in order to make the story make sense. First of all, for simplicity's sake, I had the Hellsing characters and demon slayer characters exist at the same time, despite there being a huge time gap between the animes. Also I might edit the story as I read more of the demon slayer mangas. And finally this is told from a third person omnicent POV
The death of Kyojuro Rengoku stirred up a lot of worry with the demon slayer corps.
The hashira all gathered inside the Ubuyashiki mansion and discussed the issues at hand. Shinobu was furious and pent up with rage over rengoku's death, though didn't show it. Gyomei had made many silent prayers for Rengoku. Obanai, Sanemi, and Uzui were arguing over how the outcome of the fight could have differed had Inosuke or Tanjiro acted faster. Giyuu and Muichiro were sitting silently contemplating what had just happened.
The arguing came to a hault as a man, being guided by two small girls, entered the room. Kagaya Ubuyashiki was only growing more and more sick as weeks went by, and he had no doubt that he would soon be rejoining Kyojuro in the afterlife.
He sat on the floor facing all the pillars, who had now organized themelves and were sitting in a respectful manner. "It is becoming more and more clear that the upper rank demons are becoming too strong for even our most powerful swordsmen", announced Kagaya, " and I fear that they may even overrun and completely destroy the Demon Slayer corps."
This sent whispers of worry amongst the pillars. And in no time, arguements started to break out.
"WE WOULDN'T BE IN THIS SITUATION HAD YOU SENT ME!", exclaimed Sanemi, who saw himself as superior to Kyojuro.
"Shut your trap", said Obanai, "We just need to train these weak, new generation slayers better and more intensely."
"Shut up Orochimaru, with your lame azz searpent breathing", said Sanemi.
"It is a lot more original and powerful than your weak azz wind breathing, man what the F*ck is that supposed to do to demons."
Eventually, they all started to argue again, dspite their master sitting right in front of them. Kagaya was more sad than annoyed. He whispered something to Gyomei, the only one who was sitting silently, and Gyomei got up
"hey..." he said quietly, "Hey", he said a bit louder.
"HEY!" He screamed with all his might, knocking over Mitsuri with a loud shockwave. This got all the pillars' attention and " Master has an announcement."
"Very much appreciated, Himejima" He spoke in a soft tone
"Due to our recent problems", he sighed, as if embarassed," I have enlisted the help of an organization called Hellsing."