Weba lot of things happened during the final episode, the most important of which was kagaya ubuyashiki and his family’s death after the appearance of muzan kibutsuji.
Webdespite his fearsome reputation among slayers and demons alike, muzan had an illness that almost took his life in demon slayer, resulting in his intense fear of.
Webgen’ya could modify his inserted flesh balls even further by making them penetrate his target’s body and absorb demon blood, stopping them from using their own.