Merlin

Merlin (マーリン) is a fictional character from the manga series of Shaman King. She is a shaman and a member of Team "Magical Princesses".

Past
Merlin is an English witch. During the war, she served the Prime Minister using Beelzebub, the spirit of flies, and used insects from around the world to collect information that was difficult to obtain even for the secret services. She saved her country several times this way. Today, however, no one has much need for her and she has fallen from grace, barely being able to make a living as a street keeper. By comparing the teachings handed down orally by her ancestors with the documents preserved in the British Museum, Merlin is convinced of the existence of the Shaman Fight and, seeing it as an opportunity for a new life, dusts off her techniques.

Anime/Manga Difference
She is a manga only character and is never shown in the anime series.