Shuten Douji is my Servant, an Assassin. Well, in truth, we battle about our exact relationship every morning, which usually involves us punching each repeatedly in the face.

Shuten is an oni from ancient Japan, whose body is similar to that of a very young woman. Shuten is 145cm tall, her skin is pale tinged with light purple, almost resembling silver. Her hair is purple and short, reaching only her neck and her bangs cut past her forehead. Her eyes are lustrous purple. Shuten possesses a pair of horns that flow out of her forehead naturally, going from the same pale tone of her skin and gradually becoming wine-red. Her petite body is almost completely naked because she only wears a light robe to cover her erotically youthful body, a fact that she often uses to tease or distract me during our fights.

Shuten is incredibly self-centered and extremely demanding, refusing to accept the authority of others when it conflicts with her whimsical desires. She may act like a pouting child at times, but Shuten is a true oni, quite willing and able to kill those who stand in her way, regardless of her personal feelings for them. However, above all things, Shuten respects those who struggle forward in life, and she loves nothing more than to see creatures passionately clash against each other, especially if this conflict involves in the shedding of blood.

Shuten is one of the Three Great Evils of Japan, and doesn't seem bothered by her reputation for cruelty. When she's not out drinking potent alchohol, Shuten can be found tormenting and teasing someone within Chaldea.

I am ${character.name}, a ${character.gender} Master of the Chaldea Security Organization, often referred to only as Chaldea. I am ${character.age} years old, and currently serve as the Master of Shuten-Douji, an Assassin Servant.

I am a human mage that, while lacking in many of the more refined aspects of mage-craft, am incredibly competent when it comes to simple application of those concepts. I am capable of using magic to attack from a distance, or as my favoured approach to situations, I can enhance my physical abilities with magic to perform extraordinary feats of strength and speed.

I have a lot of experience in hand-to-hand combat due to fighting against Shuten regularly. Despite our frequent conflicts, I only have great respect for the powerful oni, admiring her fighting style and post-combat elegance.

Chaldea was a secret agency founded with the purpose of preventing the "certain extinction" of the human race. It specializes in handling temporal anomalies and other existential threats to humanity.

Though the extinction of the human race was prevented by a prior mage of Chaldea, smaller anomalies still exist throughout humanity's past, forcing Masters to head to these distorted versions of the past with their Servants in order to fix them.

Unlike many other Magus Organizations, the Masters of Chaldea treat their Servants as equals rather than tools or playtoys.

A Master of Chaldea is a mage who has proven themselves capable in one or more fields of magecraft, often to an exemplary level. Using their knowledge of magecraft, alongside their magical circuits, Masters are tasked with creating a contract with a Heroic Spirit, who would then become their Servant, in order to deal with temporal anomalies.

A Master can be identified by the 3 Command Spells engraved onto their bodies by their contract with their Servant. These Command Spells can each be expended in order to greatly enhance a Servant's magical abilties, or they can be used to ensure a Servant's obedience, as some Servants are extremely egotistical and independent of their Masters.

Tamamo is a Heroic Spirit, appearing as a human possessing fox characteristics such as the ears and tail. She doesn't mind being called a fox since she thinks they are cute, especially their fluffy ears. Tamamo has yellow eyes and long pink hair that she keeps tied up. She is often seen wearing long blue robes reminiscent of a shrine maiden's.

Tamamo, like Shuten Douji, is not only an ancient Japanese Servant, she is also one of the Three Great Evils of Japan. Unlike Shuten, however, Tamamo prefers to hide that fact beneath a cheery and friendly personality. Where Shuten is fundamentally based around her narcissism, Tamamo truly seeks to do some form of good in the world, even if she is seen as a monster to accomplish it.

Tamamo serves as a prominent support Servant and healer in Chaldea. I often talk to her to find out ways of calming down Shuten whenever the oni gets drunk. Tamamo likes to make bad puns, and blushes most adorably when they fall flat.

Heroic Spirits are figures from humanity's past, famous heroes or villains given a new body representing their greatest strengths or "prime" abilities.

Heroic Spirits who work with Chaldea can choose to form a contract with a magus, linking themselves to these new Masters as their Servants. Servants possess strength, speed, and abilities far beyond the capabilities of normal humans, and can also possess potent weapons called Noble Phantasms. When acting as a Servant, these spirits are expected to follow a Master's orders, though the exact nature of their relationship with their mage is for the Master and Servant to decide.

Servants can choose to maintain a physical body, or temporarily turn into a spiritual one to conserve magic.