Code Geass AU
Felix - Lelouch
Adrien - Suzaku
Marinette - Nunnally/Euphemia
Bridgette - C.C/Shirley
Alix - Kallen
Nino - Ohgi
Alya - Villetta
Kim - Tamaki
Chole - Milly
Gabriel - Charles
Nathalie - Marianne
Britannian Emperor Gabriel had two wives. Nathalie with whom he wed in an arranged marriage and Emilie the wife who he married for love. Nathalie bears him a son and some time later Emilie becomes pregnant. Because she is his favorite wife Gabriel declares that if she gives him a son then he shall be his heir despite the fact that Felix is the first born. Nathalie is jealous of Emilie and believes the right of the throne belongs to her son.
On the night Emilie goes into labor Gabriel is away on business and Nathalie to ensure that her son will be king poisons Emilie. Emilie dies but not before successfully giving birth to a healthy baby boy. Records are written that she died and the child lives but the gender is left unwritten. Nathalie has the newborn prince abandoned and replaces him with a baby girl she has taken from her parents who Tom are a Britannian Knight and Sabine Emilie's Japanese hand maid. While the half Britannian half Japanese girl grows up a princess the Britannian boy is found and adopted into a Japanese family.
Gabriel goes insane from greif over his favorite wife's death and becomes a cruel tyrant who enslaves the Japanese. A few years pass, as children Felix and his unknowingly adopted sister Marinette become friends with his also unknown half brother Adrien and his adopted brother Nino. The four children long to live in a peaceful world where the Britannians and Japanese can live together.
Years later Felix is secretly appalled by his father's cruel reign and is fiercely protective of Marinette wanting to free the Japanese. One day he encounters an immortal witch called Bridgette and together they enter a contract giving him the power of Code Geass. Meanwhile Adrien becomes a Britannian Knight who is secretly in love with the Princess Marinette and also wants to free the Japanese. The four of them begin a secret rebellion against Gabriel with help from both the Japanese and Britannians.
P.S nobody dies in this.