Ikaruga Civil War
Lambda's corpse was left in Ibukido in a coffin next to Mu-12 and Nu-13. Lambda was eventually left alone in the rubble, as Mu was rescued and adopted, and Nu was retrieved by the Novus Orbis Librarium. Iron Tager later found Lambda under the orders of Kokonoe. He took her back to Sector Seven before she began to rot, and Kokonoe managed to bring her back from her death, but refused to bring back her memories since they would be too painful. 
A bio-weapon given life by Kokonoe. She is a "Murakumo Unit" made from a fusion of the body of the 11th Prime Field Device recovered by Tager from the Sheol Gate, and the soul of the lost 13th Prime Field Device (ν -13-). Having completely lost her memory, she is currenly being used to fulfill Kokonoe's goals.
An imitation "Murakumo Unit" created by Kokonoe using the recovered body of the 11th Prime Field Device recovered from Ibukido. When she lost her body and disappeared, she entrusted the Idea Engine to Ragna, who was in a crisis. She then awoke in an unfamiliar location, having lost all of her memories — about herself, and about Ragna...
An imitation "Murakumo Unit" created by Kokonoe using the recovered body of the 11th Prime Field Device recovered from Ibukido. She receives an order from Kokonoe to search for the "Grim Reaper" that possesses the "Azure Grimoire," but whenever she hears the name "Ragna," she reacts.
Resurrected inside the Embryo, Lambda forgot that she had died once. Her memories were also altered to believe that Bullet had always been a member of Sector Seven. Even in the Embryo, Lambda still served under Kokonoe, and she was able to became one of the chosen.
She alerted Kokonoe to a change in seithr concentration within a distorted Kagutsuchi.  Kokonoe sent her into the Embryo above Ibukido, and later retrieved her. Much later on, Lambda was reunited with Ragna and she helped him, Tsubaki Yayoi, Hakumen, Ex Machina: Minerva, Jin Kisaragi, Kagura Mutsuki, Rachel, and Noel to enter the Embryo's frozen space-time. She held open the entrance by linking her Idea Engine to Tager's. 
Lambda watched Tager evaporate into seithr during Doomsday and had her data backed up by Es before she too disappeared.  Lambda was reborn in the new world created by Ragna the Bloodedge, becoming a nun alongside Noel. The two of them watched over Nu, who was in an almost catatonic state. They had a visit from Tsubaki and Makoto, and offered them dinner. 
- BlazBlue Material Collection, Iron Tager Short Story - Trust You
- BlazBlue: Continuum Shift Extend Official Site (JP), Λ -11-
- BlazBlue: Chrono Phantasma Official Site (JP), Λ -11-
- BlazBlue: Central Fiction Consumer Edition Official Site (JP), Story - Λ -11-
- BlazBlue: Central Fiction, Story Mode, Episode 002, Chapter 009
- BlazBlue: Central Fiction, Story Mode, Episode 011, Chapters 088 – 089
- BlazBlue: Central Fiction, Story Mode, Episode 011, Chapter 091
- BlazBlue: Central Fiction, Story Mode, Episode 012, Chapter 100