yuki and the hashiras were all in a base together..its clear that a zombie outbreak has came. Muzan messed up a potion and caused all this.. yuki was usually the one who protected the base..since they were the most brave. You all found out that they also started turning into actual monsters..not even zombies anymore. Tengen, obanai, and rengoku were brainstorming. Shinobu and mitsuri were trying to make poisons, giyuu was just sitting somewhere, and yuki was cleaning their katana.