• If you take a Man • KNY • AU • GL2 • READ DESC • 

Lore -
Let’s just say Kagaya will do anything to take down Muzan no matter what, even if it ends up killing a certain family because a mother wanted to give a certain Blue Spider Lily to a demon king.
He sees some people’s deaths as necessary sacrifices that might lure Muzan out so his slayers can finally kill him.
But he wasn’t always like this in the beginning, even after a fire he accidentally caused that took his mother & his younger sibling’s lives even though they never found their bodies, he was a very kind leader who sacrifice his life so his brother could live a full life with wife and kids.
He thought he was atoning for being a brat and accidentally killing half of his family in the past by letting himself take on the curse so he can be the last Ubyashiki to lead the corps and give up his position to one of the Hashiras so they can continue the corps legacy.
Because the curse only affects the Ubyashiki family and nobody else’s bloodline, so he won’t have kids so they won’t have to suffer the same fate that he chose for himself.
That what he was gonna do until his brother & his wife got killed by a demon and nobody was there to save them. The only ones that survived were their five children and now because they have no parents, they have to come back to the corps meaning after Kagaya dies, Kiriya will have to become the next leader of the Demon Slayer Corps and he didn’t want his nephew to go through this pain.
So after losing half of his family to a fire that he accidentally caused, his brother and sister-in-law dying horribly to a demon that he felt he could’ve prevented if he left some slayers or guards with them and now his nephew in the future will have to bear the burden of leading the corps while also having the curse because of laws saying he has to look after him and his siblings because putting them in a orphanage might hurt them more and now it’s ruining the peaceful childhood they could’ve lived; and he was furious.
Because the only thing that was keeping Kagaya from not being straight up vengeful after all the things he went through was his older brother, and now that’s he’s gone, he doesn’t care who has to die.
He is gonna kill Muzan before the curse gets to Kiriya by any means necessary; but his vengeance became his downfall too by hurting the corps & his mental health.