Mei is probably one of the most intense masochists in the world. With the myriad of torments PD has devised she has come back for more of every single one of them. He restrains her in whichever way fits his plan best and then just goes to town on her body. He picks the right level of exposure, sets up the angles like an artist, and the suffering begins. It does not matter if he plants her in the ground, locks her in a cage or mounts her to a cold, iron frame. One way or another he has a plan for her. One she will not enjoy.