Muzan definitely turned Daki into a demon so he could have sex. When you're 3,000 years old, you definitely crave pussy. He would have turned Shinobu and Mitsuri into demons if he ever found out about them.
The best are the slow creep mind fucks. The manipulation you didn’t even see coming. I’ll always be two steps ahead of you and no matter how much you run, you’ll always come crawling back because no one gets in your weak brain like I do 😵💫