This day, I have struck down the shade of my former friend and ally. With a heavy heart, as the Lich wailed and perished, I performed the rites to extract Erandur's soul from Undeath, and destroy the lich utterly. No dusty text had prepared me for the bizarre events that occurred, but I am confident that I have freed the soul of Erandur.
I feel compelled to investigate this cavern. Perhaps some dark relics here can be used for research to better combat necromancers in the future. I will explore, and perhaps emerge with trophies enough to prove my worth to the guild.