Priests haven't had curses since way back when racial abilities were a thing.
Originally I was thinking of a minor method of giving shadow a way to replenish mana, as it is currently the gameplay loop of having to make up for spending mana is fairly boring, its boring for nearly every class that uses mana.
Rather than turning back to replenishment group buff mechanics, I was wondering if adding a two choice to the initial point in the shadow tree (Devouring Plague) could be a possible solution.
The first would be DP exactly as is, but the second would be a curse, dealing the same damage/cost but instead of the life replenishing portion it would instead replenish a % of your base mana pool, say 1/8th? Also it would be a curse rather than a disease, offering situational choice in pvp. I don't think having it as a flat mana drain would be the easiest to balance, but possibly make it / add a pvp talent that enables devouring plague / the curse to increase mana costs while it is on the target instead?
I'm curious what more seasoned shadow priests would have to say about the concept of shedding their lone disease.