The purpose of pathetic BDSM slave’s loss in the oriental animation

In this video, a number of BDSM slaves are shown being dominated and defeated by anime characters. The particularistic sex scene is a domination-sex-submission scene, and they are in a dungeon-like room: the BDSM slave is cuffed, hooded, and tethered with metal, with a ball gag in her mouth. Both the dominant characters have their turn to demean the slave and show a powerplay involving several measures of BDSM.