Shan was betrothed to Elend Venture by their parents, though he did not want to marry her and neglected her in the hope that the engagement would be called off.
Though Shan was beautiful and elegant, she was known as one of the most arrogant of the young nobles.She spent much of her time deriding, insulting, and demeaning her peers.
There were rumors among the nobles that Shan was a Soother. She often used the power to manipulate less powerful nobles. She was able to convince them to do what she wanted and keep them in fear and awe of her. There is no record that she ever used another allomantic power openly in public, presumably to hide that she was not a Misting but a Mistborn. However, she could have used her powers secretly if she first burned copper to hide it. If she did so, only a Steel Inquisitor could have detected it.
Shan knew Elend read books banned by the Lord Ruler. When tensions between the noble houses flared, she attempted to obtain proof of it, knowing that it would probably result in Elend's execution and disgrace for House Venture.
Shan later attempted to kill Elend, with the cooperation of Straff Venture. She led an assassination team of allomancers, which included another, unknown Mistborn. Vin discovered the plot from Kliss and arrived as the assassins were approaching. When she saw Shan, she realized the noblewoman was actually a Mistborn. Vin threw a man through the skylight to alert Elend and his friends, then began fighting the allomancers.
When Vin tried to flee, Shan chased her. After an extended battle, Vin tricked Shan and killed her with an arrow.