As a reaction, which you use when a humanoid dies within 5 meters of you, you can magically capture its shadow. You retain this shadow until you use it or you finish a long rest.
You can use the shadow as an action to adopt the humanoid’s persona. When you do so, the shadow vanishes, magically transforming into a disguise that appears on you. You now look like the dead person, but healthy and alive. This disguise lasts for the duration or until you end it on your turn.
While you’re in the disguise, you gain access to all information that the humanoid would freely share with a casual acquaintance. Such information includes general details on its background and personal life, but doesn’t include secrets. The information is enough that you can pass yourself off as the person by drawing on its memories.