A slave is a slave for a reason. They are there purely to satisfy their mistress in whatever capacity is required of them. This might be cleaning the dungeon, being used to assist mistress in her sessions or just simply being there to receive some pain. For this slave, it is purely for Mistress Kiana's enjoyment.

Commanded to eat Mistress Kiana's pierced pussy and then riden as a piece of human furniture. The slave is nothing more than a humping post with a tongue but for Mistress Kiana's pleasure.