Archmage Merlin appears to be a slender, long haired female wearing a skirt, but is actually a man. He has a glib tongue, and is proficient at sweet talking as he did in order to appease the South and ask for her retreat. As an archmage, he wields great powers, so much so that even the South is cautious around him, and that he is able to manipulate a magic circle on a scale as large as the city.
Background
Merlin is the protector of Britain and the entire city of Camelot is designed in the form of a magic circle for his disposal. He is the strongest and only archmage alive, and has the look of a female as a result of his actions to obtain a source of mana. He is known to have disappeared right after King Arthur's death.
He was first mentioned by Diana Basil for Tasha to approach to power up Halloween with a sword that will restore her former powers. This sword may be the legendary Excalibur.
He first appears before the South and redirects her attack away from Cooga Kunein into another part of the city, and has returned because there is now someone to serve, referring to Halloween, the daughter of Arthur. He currently demands the termination of the contract between Tasha Godspell and Halloween in exchange for the information of the location of the Four Great Witches.