Gloomdoc made its way quickly to the top of the Shadow religion simply by murdering every single other Shadow Priest. Not only did this leave it as the only available candidate for the High Priest role, it also greatly pleased the gods of Shadow. Truly, Gloomdoc is the perfect fiend for the job.
Its role in battle is to heal allies by casting a black cloud across the arena. The evil part is that any enemies caught in the cloud get blinded, and are therefore unable to adequately defend themselves against assaults from Gloomdoc’s freshly healed comrades.
The difficulty in deploying Gloomdoc is that the black cloud only moves in a straight line, and getting its allies to stand in single file is difficult enough, never mind its enemies. But there are times when allies in need of healing and enemies in need of blinding do line up in front of Gloomdoc at just the right time, and under those circumstances, the black cloud can turn a battle on its head.