Thetis

is Queen Elizabeth's personal magician and the best one currently serving the Kingdom of Liones.

Chaos in Liones arc
Thetis remains inside the castle as the battle against Arthur Pendragon takes place, laughing as she feels Lancelot fight.

On the night after the battle, Lancelot tells Thetis that she is weird for praying for the deceased Galand and Melascula who killed thirteen people, to which Thetis replies that she only feels sorry for them and that it was twelve people. Thetis reprimands him for allowing Jericho to kill the prisoner who was their only foothold to get to Camelot, to which Lancelot excuses himself by saying that he could not lift the magical restraint Thetis placed on the prisoner. As Lancelot say that she does not understand how he feels and calls her an old hag, Thetis reminds him that they have the same age and that he does not understand her feelings neither, since reading minds and understanding feelings are two very different things. Tethis leaves telling Lancelot to cool his head with a night breeze.

Current arc
Thetis was present during the audience between Percival's group and the king. She introduces Elizabeth as the queen of Liones and gets annoyed by Meliodas's actions.

She then participates in the meeting in the war room to discuss the situation with Camelot. Thetis reprimends some of the attendants for being noisy and urges Meliodas to get started. When Anghalhad ask why are they fighting a kingdom that was destroyed 16 years ago, Thetis explains that Camelot was recreated in an alternate dimension by the power of Chaos but are now starting this war because there is a price to pay in order to rebuilt and maintain the new Camelot. To further expose her words, she uses her magic to teleport everyone to a landscape that has been stripped of various parts, leaving only empty spaces.

Thetis says that the erased mountain used to be a premium quality ole and that it was surrounded by forests, lakes and many small villages, such as Ordan, Cebron and Igor. When Percival says that they must go to Camelot to stop Arthur, Thetis recites a prophecy spoken by King Bartra that when the Four Knights of the Apocalypse are reunited, their hope will be lost at the hands of a Chaos assassin and the sword of a traitor. Thetis explains that although an omen is not an ability to see the future with accuracy, it is an essential power to take the initiative against Camelot, which led them to believe that the enemy was after Baltra, although in reality their objective was the prisoner of war that was to be used as a key to Camelot, who was killed by a former Holy Knight of Liones, Jericho, after seeing that she could not free him from the magical restrictions that Thetis placed on him. When Donny and Percival ask Meliodas why he didn't go to Camelot himself while he could instead of waiting for the Four Knights, Meliodas replies that he couldn't because he is a demon, leading Thetis to explain that Camelot is protected by a barrier that prevents any race except humans from entering. As Meliodas says that they entrust everything to the Four Knights of the Apocalypse for being humans and half-humans, Thetis says that it is normal that Camelot's barrier does not affect half-humans since it has never been heard of beings born from two different races and also that would have reduced the defensive capacity of the barrier. When Tristan interrupts her to point out that they're at a dead end by not being able to go to Camelot, Thetis and the rest can't come up with a solution, leading Percival to suggest they just go on an adventure to find one.

Abilities/Equipment
Thetis is a very skilled magician, enough to be appointed as the queen's personal one.
 * High-level teleportation magic that allows Thetis to appear and disappear at precise locations and teleport groups of people instantaneously.

Weapons

 * Staff

Lancelot
Thetis and Lancelot seem to know each other for some time.