So far other hard quests have a clear lore, that is somehow related to the Tibia common world (meaning the life in mainland), for example, in Soulwar we fight against Goshnar (Ferumbras grandfather) personality shards to avoid them escaping into the living world. And in Primal Ordeal the gnomes dig deeper (one more time as if they have not learned from their past mistakes) and find an extremely powerful primal world, which we need to help them deal with as we have done in the previous warzones.
So, what would be the lore of the Rotten Blood quest, and how is it related to the common world of Tibia?