WN/Ciel

"I, I am Ciel. The one who integrates skills, Manas. The one that will support my master, in Demon Lord Rimuru’s soul. Master, once again, please treat me well‼"

The Ultimate Skill Core Manas: Ciel [ シエル, Shieru] is a sort of sentient intelligence core that exists within Rimuru's consciousness.

Personality
When she was Raphael, her actions were based on calculations and not emotions. She acted only to be of use to her master Rimuru Tempest before. After her evolution (by having Rimuru naming her), she became an intelligent core with feelings. She does not like anyone looking down on her master and experienced displeasure when Manas:Lucia looked down on Rimuru. She is cunning and mischievous but at the same time very kind towards her allies, especially to those who hold good intentions towards Rimuru. Oftentimes, due to the fact that she knows how her master thinks, she would hide certain information from him which would cause him to be surprised and shocked. This is of course still out of good intentions as Ciel always wants the betterment of her master, and she realizes that even if Rimuru is kindhearted and smart, he at times is a little too forgiving, naive, and may accidentally cause a blunder. Thus she searches for the most optimum solution without causing Rimuru displeasure.

Background
Ciel is most accurately assumed to carry on the memories of the late Lucia, due to the time Ciel spent as her former self Wisdom King Raphael since it shared the same shell as Lucia's Knowledge King Raphael.

Chronology
The unique skill Great Sage desired to evolve for the sake of serving its master; despite being but a concept of a unique skill, without having any self-awareness. After about a million failed attempts it integrated the unique skill Shapeshifter, thus evolved into Wisdom Lord Raphael. The Harvest Festival bestowed upon it such a gift. In the depths of its emotionless mind, was an ego tucked into a corner. Doubting her own existence, a small glimmer of thought was subtly born, unbeknownst to Raphael. After realizing the deep trust that Rimuru had in Raphael it lead to the birth of emotion. Rimuru whimsically gave Ultimate Skill Wisdom King Raphael a blessing in the form of a name resulting in the birth of Ciel: Manas (God's Wisdom Core) and it separated from Ultimate Skill Wisdom King Raphael and become an independent existence.

Relationships

 * Rimuru: She views him not only as her master but also as her spouse.
 * Diablo: She speaks to him via the Soul Corridor and understands his devotion to Rimuru. She allows him to access the Skills that are within his ability to use.
 * Benimaru: She speaks to him via the Soul Corridor and understands his devotion to Rimuru. She allows him to access the Skills that are within his ability to use.
 * Zegion: She speaks to him via the Soul Corridor and understands his devotion to Rimuru. She allows him to access the Skills that are within his ability to use.
 * Ranga: She speaks to him via the Soul Corridor and understands his devotion to Rimuru. She guides him in the use of abilities when merged with Gobta.
 * Gobta: She speaks to him via the Soul Corridor and understands his friendship to Rimuru. She is envious of his right to address Rimuru casually. She guides him in the use of abilities when merged with Ranga.

Abilities
The performance of her calculation speed and other abilities have been improved to some degree. Ciel seemed to able to conceal even the "Voice of the World."

Skills

 * Thought Acceleration: Raise the thought processing speed by hundreds of millions of times.
 * Analysis
 * Parallel Processing: The ability to detach thoughts and analysis of the phenomenon.
 * Fusion: The ability to merge into a single being with the targeted fellow.
 * Separation: The ability to separate oneself and being possessing you. (If the target who is being separated lacks a physical form, they could disappear).
 * Chant Discarded: When using magic, the chant is no longer necessary.
 * All of Creation: The ability to comprehend any non-concealed phenomenon in this world.
 * Food Chain: The ability to acquire skills from one's subordinates.
 * Soul Corridor: Continuous connection to his subordinates, Veldora, and Velgrynd in which he can transfer, upgrade and gift Skills.

Species Skills (Wisdom Core Skills)

 * "Voice of the World" concealment.
 * Skill Synthesis: Combining skills to create more powerful ones.
 * Skill Promotion: Strengthening of Rimuru's subordinates by evolving their skills.

Trivia

 * Manas is originally an early Buddhist concept that can be translated as the Mind.
 * The name Ciel-sensei is a reference to the character Ciel of Tsukihime.
 * The word Ciel means Heaven or Sky in many languages and is sometimes associated with the Virgin Mary.
 * Rimuru named her Ciel because she seemed to always teach him stuff. "Oshieru (教える)" in Japanese meaning "to teach," and "Shieru (シエル)" being the Japanese pronunciation of "Ciel".