Miko

The Miko is a girl with a Miko Power that gives her the ability to see memories by looking into people's eyes.

Miko Power - Telepathy
When looking into someone's eyes, Miko is able to see one's "surface memories", memories that a person has in mind. This also extends to being able to see related memories to that subject, and the longer she stares into someone's eyes, the more of that person's memories she sees.

This makes her perfect for interrogations, because when asked a question regarding a crime, it's impossible for someone to not think of the question or its answer. This is often how her powers are used.

Trivia

 * In the original timelines where Rudeus didn't exist, she never reaches past the age of 30 and usually dies around the age of 10. Since she is perfectly healthy, it was likely that all other times when she met her death was by the hands of assassins.