She tried to tell the truth to the necromancer on what MC is doing behind his back but fail due to MC acting skills. The reason she is doing this is hoping that her slave treatment will get better but instead it's getting worst on each report. MC found out what her true wish is and used her as information gathering and some minor work. This soon lead to inviting the Holy Knight into the home base which are covered with a barrier that are only able to reach into only by using some sort of invitation method (it's like how vampire only able to enter the house if they are invited). During at the end of the first arc, necromancer use slave command on her as a bait to stall the movement on the holy knights that was attacking the home base. She was killed by holy knight. At the end MC reveal that her real wish was to die so she can end the suffering and made a promise with MC to make a grave for her. MC did make her a grave at the end of the battle, MC impaled a silver arrow that was used during the battle on her grave to ward off any wicked things (MC did receive pain while holding the silver arrow). MC gave her his second(family) name since he doesn't know her name and felt that it would be lonely without one. MC engrave her name on the tombstone "Ruu Carmen" and prayed for her to sleep peacefully.