Leticia Draculea

Leticia has a quiet and reserved personality, and she usually is cool and stoic. She is a former Demon Lord, and Black Rabbit says that she is one of the rarest for being a vampire, a pure-blooded vampire at that. Because she's a vampire she's often called "Knight of Miniature Garden", which is a title earned by her race for what they have done in the past.
She has the power to control darkness and shadows.

It's later revealed that she has lived a very lonely life, having been alone for thousands of years before meeting the NoName community, and having lost most of the people that she ever cared about.

(Source: Wikipedia, Mondaiji Wikia)