Sasha is Joseph's older sister, and a rarity among immigrants in Germany that she graduated from a public university despite her background and origins.

Presented as a kind-hearted and cheerful woman, Sasha was loved by both Joseph and Xargin, who was interested by her research in the field of nanomachines, which he thought was for the purpose of aiding the medical community. This however was a lie, as her work was for the military, which was bent on the development of biological weapons. She was beaten to death by racist citizens, and died due to the injuries she suffered. She reappeared years later at Zwölf HQ, revived as a cyborg with much of her body rebuilt, shorter white hair, and a cybernetic green eye which replaced her original left.

She also had a number of plugs along the left side of her face and in other parts of her body, such as her neck. Much colder than before, Sasha is one of the Apocalypse Knights and the pilot of the Bow Rider; a powerful energy cannon that doubles as a bipedal white mecha focused on long-range fire support. Plagued by what she had created back when she was human and what her brother had to endure, she sought atonement by means of death, and defends Germany from the impeding nuclear strikes at the end of the series with Mei Feng and Shido. She dies when the Bow Rider overheats and explodes with her still inside it.

(Source - Blassreiter Wikia)