C145 Repeated Pen Fairy
Yun Duruo and Nangong Yi were both girls, so upon hearing my suggestion, they probably remembered the four corpses hanging from the ceiling fan in Room 403. From the looks of it, they seemed to have some lingering fears.
Pen Immortals were the same type of sorcery as Taoists' Pen Immortals, so Han Yu was familiar with the process. Pen Immortals had to get to places with more Miasma