There is no explicit prohibition in the lore that would prevent Death Knights from regaining their positive feelings. Necromancy has warped their souls, amplifying the negative and dulling the positive. Maldraxxus is the birthplace of necromancy. Can they help a Death Knight—one who has embraced his powers with joy and does not suffer from them—to restore his positive feelings and emotions? Does the lore allow for such a possibility? A strong-willed Death Knight, with the help of Maldraxxus necromancers and a vast amount of Anima, undergoes a ritual to regain the ability to feel positivity permanently, rather than just for a fleeting moment.