I should mention my second monitor only got a VGA port <| sep |> I personally explain my Priest switching between Holy and Shadow with her mental problemsOld God corruption . She wants to be good , studied the Light and can use it . But at a young age she succumbed to the whispers of the Old Gods perhaps she was bullied or afraid of a task . She didn ' t think she ' s strong enough and fell for the promise of power . She managed to take control back , but when she ' s weaken , scared or unsure , she loses it again , goes mad and uses the power granted by the Old Gods . Obviously at that point she ' s under their control and as such she can ' t use the Light . But with the help of the Light , probably she can take control again , going back to being a normal , nice Priest .