Neptune

Saturn's long lost sister. Hasn't been seen since the Pokemon Go'ing Arc.

Backstory
In 1941, during World War II, The Boss was invited to the SAS as a special advisor, which resulted in the creation of Layforce and the original L Detachment. There she met David Oh, with whom she later formed the 22nd SAS Regiment. She also planned the dummy raids on Heliopolis and the bombings of German air bases during the North African Campaign.[4] In addition to this she participated in many "snatch" missions, in which she had to capture important officers without killing them; the incidents later served as the basis for her development of CQC.[5] According to Major Zero, the SAS motto, "Who Dares, Wins," was a tribute to The Boss.

On December 30, 1941, she and Zero lost a close friend who had served under her in Layforce (likely during Operation Crusader in Egypt). Zero delivered his SAS winged dagger pin to her after his death and she continued to keep it with her right up until her death.

In 1942, The Boss (then known as The Joy) founded the Cobra Unit, which consisted of herself, The Pain, The Fear, The End, The Fury, and The Sorrow. They participated in many special operations during World War II, contributing heavily to the Allied forces' victory. Likewise, she was also trained in sniping by The End. The entire Cobra Unit looked up to her as their mother and leader, and she formed a close relationship with The Sorrow. The Boss became a legendary soldier, and was considered by many to be the "Mother" of America's special forces.

In 1943, The Boss was ordered to infiltrate Los Alamos and assassinate one of the Manhattan Project scientists, John von Neumann, under the belief that he was a Nazi spy, and make it seem like his death was accidental. But just before the operation, she found out that she was pregnant by The Sorrow. She proceeded with the mission as planned, though she ended up blowing her cover due to being distracted by her pregnancy. Though she avoided a bullet aimed for her gut, she received a graze to the side of her brain and would enter a coma for three months. After six months, The Boss made a complete recovery, theorizing that her body may have willed her to live for her child. She grew to regret failing the mission, even after it transpired that Neumann being a spy was actually Soviet misinformation to sabotage the Manhattan Project. The Boss felt that his living resulted in the Cold War, which made her partially responsible as well.