The ability to swap brains

Ren gave himself the ability to swap people's brains. Not just with other brains, but with items or even animal brains. All Ren had to do is unscrew someone's head and pluck out their brains, then put whatever he wanted to replace their brains with, and the person would think they were whatever their new brain was. So if Ren swapped Ann's brain with Sumire's, Ann would think she was Sumire and vice versa, and if he replaced Sae Niijima's brain with a pillow, the ace prosecutor would think she was a pillow. And what's better, Ren made sure his wish would make it so that any objects which were put inside the woman's head would immediately be shrunk down to fit in there, and not cause discomfort. Ren also made it so that the women were viewed as whoever or whatever their brains were swapped with by everyone else.