Rumor of the female members of the Demon Slayer Corp being turned into beautiful half-deons soon reached Daki's ears, who had to see it for herself. There, her worst fear came to reality when she saw a corrupted Kanao now possessing even bigger assets than she is. The mare thoughts of others becoming Muzan's new favourite drove her to anger. However, as Muzan had already given out orders not to harm the corrupted slayer. Frustrated but unable to do anything, Daki soon became deeply depressed. Fortunately, Kanao had brought with her a condensed formula of Shinobu's blood extract, and she was more than happy to hand it to Daki. Willing to do anything to remain in Muzan's grace, Daki drank the liquid. Soon, her body began to fuse with that of her brother, who was slumbering with her. Despite knowing that, Daki didn't give it much thought at the time, as the only thing on her mind in that very moment was pleasing the Demon King.
Returning to her post, Daki immediately sought out Muzan for approval. However, unknowing to her, Muzan wasn't too pleased with her actions, since fusing with her brother had deminished their overall capabilities. Fortunately for Daki, he still had some uses for someone as loyal as she was.