- "If I must become a harbinger of ruin to create a new world...the world that he (Zero) seeks to create...the world where Nunnally can be at peace... Then so be it!"
- ―Lelouch vi Britannia
Lelouch is the pilot of the experimental UW-XXXX-001 Zero Gundam unit, an advanced Mobile Suit equipped with the mysterious black box system: the ZERO Drive. After aiding the Order of the Black Knights in defending the Saitama Ghetto from Cornelia, he becomes an official member, placed under the command of Kallen Kouzuki, the pilot of the Guren Mk. II Mobile Suit.
Lelouch is a handsome, young man with black hair and violet eyes, which he inherited from his mother. Lelouch is somewhat scrawny, having little muscle, and like most characters in the series, is rather thin. In spite of this, Lelouch is considerably tall, standing at least a head taller than Kallen, and apparently being slightly taller than Suzaku.
Lelouch usually wears the Ashford Academy uniform. Outside of Ashford, he wears a crimson jacket with a black shirt underneath and gray trousers.
As a member of the Order of the Black Knights, he wears a black jacket with silver trims, and underneath it is a black sleeveless muscle shirt and black dress slacks, as well as gray boots. His pilot suit is unique in comparison to the other BK members, as it is black with red circuits around the wrists, ankles, neck, and waist.
Lelouch is a highly intelligent individual who is also calm, sophisticated, and arrogant due to his aristocratic upbringing. While at school, Lelouch conducts himself as a sociable, likeable, and often easygoing student. However, this is really a mask to hide his true nature. While as a member of the Black Knights his true nature is expressed. His charisma and beliefs in justice gain him the trust and respect of many soldiers and leaders, including Zero, who holds him in high regard.
Lelouch is known for having a very stoic personality. He never cared about schoolwork, seeing the entire thing as trivial, even though his high intelligence would make it easy for him. At one point, Shirley stated that if Lelouch applied himself in school, he could get high grades. He enjoys seeking out challenges, often playing chess against nobility. In general, Lelouch takes most day-to-day affairs with open disinterest, often not even noticing the affection of others, especially Shirley, his fellow classmate. He has a strong dislike for nobles, viewing them as tepid and "overprivileged parasites."
During the campaign against Britannia, Lelouch is a very intelligent commander, as he took over his squad's operations when the commanding officer was shut down, having them use their own units as blast boosters before exploding the Sakuradite plant, which created an explosion large enough to severely lower Britannia's fighting force in Ark 2. However, his personality begins to crumble after Rivalz takes a blow that was meant for him, resulting in his friend being shot down in front of him. The incident caused Lelouch to develop a more wild, raging fury towards Britannia, mercilessly slaughtering every Britannian unit in his path, hence earning his nickname as the White Devil. However, Lelouch had no memories of the incident, remembering only Rivalz's death. The haunting sight had caused Lelouch to waver, and his determination began to crumble as he watched many comrades die, either beside him, or underneath his command. It would even reach to the point where he refused to pilot the Zero Gundam, believing that he will only create more deaths around him in a machine that begets it.
After being reassured by Kallen, who's command he was placed under, his determination is somewhat rekindled, but is still hesitant. His strategies, which once held little care about the regard of human life, be it military or civilian, were now altered to ensure minimal casualties on civilian areas.
Lelouch was born on December 5, 2000 a.t.b. as Lelouch vi Britannia the son of the Emperor of Britannia, Charles zi Britannia, and the late Imperial Consort Marianne, making Lelouch the Eleventh Prince of the Holy Britannian Empire. He was in line to be the seventeenth heir to the throne prior to his mother's assassination and his sister's crippling in the same incident. A ten year old Lelouch confronted the Emperor afterwards and accused him of leaving his mother defenseless, even going as far as renouncing his entitlement to the throne. In response, his father banished him to Japan, where he was used as a political hostage in the Sakuradite conflict.
It was during his stay at the Kururugi household that he first met Suzaku Kururugi, with whom the young Lelouch did not interact initially in a friendly manner, before later becoming friends. However, when Britannia finally developed its Knightmare Frames fleet and decided to invade Japan to seize control of the Sakuradite mines, consequently discarding Lelouch's use as a diplomatic tool, Lelouch, fearing for his and his sister's safety, hid their true identities and sought the help of the Ashford family, who were his mother's allies.
His mother's death and his father's apparent lack of concern in regards to it were huge blows to Lelouch. He always felt that it was unfair for both his mother and sister, and therefore made it his goal to pursue a better world for Nunnally. He also seeks to discover the true reason for his mother's death, as she was murdered in the Aries Imperial Palace, a place terrorists would be unlikely to penetrate successfully without being noticed, if at all.