Cross Ange: Rondo of Angels and Dragons vs Code Geass: Lelouch of the Rebellion

Connection:

Both are female protagonists pilots from mecha animes and are considered to be unique and one of the most powerful of their respective series (Ange pilots the AW-CBX007 (AG) Villkiss while Kallen pilots the Guren Mk-II Kai)

Both are originally from a noble upbringing  (Ange was the First Princess of the Empire of Misurugi while Kallen's father is a Britannian noble who comes from a prestigious family)

Both fight an Empire (Empire of Misurugi and Holy Britannian Empire) that seemed at first a utopia, but eventually revealed their true colors (The Misurugi Empire treated Normas like animals and degenerates while Britannia is a monarchy that invades countries and names the people by numbers (Example is Japan renamed as Area 11 and Japanese citizens being called Elevens) while ). Both also joined a resistance/rebels  group (Normas and Order of the Black Knights)

Both are strong-willed, determined, loyal, and brave individuals who can also be quite short-tempered, forceful and somewhat impulsive. Despite their tough attitude, they are both actually quite sensitive, compassionate, and truly gentle at their core.

Both managed to live a relatively normal life despite being technically an enemy of the empire (Ange is a "Norma" who're people who cannot use Mana which is similar to magic while Kallen is a Britannian/Japanese with a Japanese mother)

Both have learned to accept their identity (Ange learns to accept being a Norma and Kallen accepts her Britannian heritage)