Sneak King shadow
From Twilight Heroes Wiki
Sneak King shadow
Plural: Unknown; currently impossible to determine
You stole this shadow from the Sneak King himself, which probably makes you the new Sneak Monarch. You'll probably have to track him down and ask him about the rules of succession.
And, you know, about that whole thing with giving college kids cursed talismans. That seems pretty relevant too.
Miscellaneous Item
Item cannot traded, sold, or placed in a memento display
Usable
How Obtained
When Used
It seems like this is an important clue that will lead you somewhere really useful. You know, in the future... when this quest is done.