It's actually kinda arguable which is the worst Shadowmark in 2nd edition—forgettable means that every NPC has to make an intelligence test just to remember you, but unnatural shadow has a -10% fellowship malus and causes the unwashed masses to believe that you are some kind of demon, which combined is the sort of thing that can really derail campaigns as you fail to convince them otherwise (due to the fellowship penalty) and then they try to burn you at the stake, so you defend yourself, and then they call in the witch hunters and now suddenly your players are fugitives on the run all because of single failed diplomacy check.
That part of the town is now known as "the Fire Quarter".
That part of the town is now known as "the Fire Quarter".