That 50% fire damage debuff? Yeah that's nasty, very, very nasty, in a dungeon like Blessed Crucible, you will be one shot, multiple times, on multiple bosses(Namely the fire beetles, and the last boss, The Lava Queen.) and when I say 1 shot, I literally mean you will be 1 shot, especially if you're a melee too, because you will be forced to stand in the danger zone of those hard hitting fire attacks, where they might do half health to your non-vampire group mates, it will do 95% + of your health, and you will always be a pain your healers backside. You have been warned.
"It is okay to fear the night, even the bravest warriors are filled with fright, at the sight of the might of Sithis' fang, let the blood be washed away by the rain, let the stains forever remain, another life taken in Sithis' name, another soul for the void. All hail our Dread Father and his consort, the Night Mother." -Stalks-His-Prey