Kythiirix

Kythiirix is a Spider Daedra that appears in.

At Any Cost
Kythiirix is guarding the Stone of Tusenend, and must be defeated in order to grab it.

Location
Kythiirix can be found in the Daedric ruin of Tusenend.

Trivia

 * It is worth nothing that Kythiirix may not be required to be beaten if another character has already done so recently.