Shadow of Boethiah

The Shadow of Boethiah is an aspect of the Daedric Prince Boethiah that appears before Magistrix Vox in a vision of the past showed to you by Aspera the Forgotten in Eidolon's Hollow. In the vision, Boethiah can be seen encouraging Vox's rebellion against the Tribunal and suggesting that she should claim the Judgement of Veloth for her own.

This model has a black semi-transparent visual effect applied to it in-game.

The same exact model but with a different visual effect is used for Aspera the Forgotten, further proving that Aspera is Boethiah herself.