The little brother of demons

Muzan thought that all his uppermoons were extremely loyal to him but little did he know that some of them had been secretly helping the demon slayers. Those uppermoons lived together in a little hut hidden away deep in the woods where no-one can find them. Until one day Tanjiro stumbled upon them with injuries all over his body and trembling because of the cold. The uppermoons knew they couldn't leave him like that, so they decided to look after him and he became like a little brother to them. They now have a duty to protect Tanjiro from both Muzan and the strangers who hurt him all while secretly helping the demon slayer corps. (This story contains mentions of rape and abuse, read at your own risk)