Mu -No.12- is the host vessel of Noel Vermillion. Through Yuuki Terumi's ambitions, she fused with the true Azure, and awoke as the Sword of the Godslayer Kusanagi, someone who can possibly kill a god.
Mu was made in the 5th Hierarchical City of Ibukido. As the twelfth Murakumo Unit to be made; she was christened as Mu -No.12-. Made by Sector Seven to become the heart for the Black Beast and to fuse with Hazama, the body, she was to be made in the middle of the Ikaruga Civil War to become the ultimate of Sector Seven to use against the NOL. However, this plan was thwarted by Takamagahara System as they fired Take-Mikazuchi upon the city, utterly obliterating every living being within the blast radius. Mu, in the stage of being smelted, and thus, in a cocoon, was saved from the same fate as the others, but left without an identity. She was later found and then subsequently adopted by Edgar and Claire Vermillion and christened as Noel Vermillion. Though in actually Mu was possessed by Noel who the original prime field and the Master Unit Amateratsu using her as a vessel.
Moments after Mu was awakened, Yuki Terumi gave her the order to destroy the Master Unit, Amaterasu. She goes to the open Gate, where she fights Hakumen and Jin Kisaragi, defeating Jin. When Ragna the Bloodedge arrived, he finally defeats the Godslayer by awakening Noel's mind, but sacrifices his left arm in the process.
Thanks to Rachel Alucard, Noel regains Mu's powers and abilities in order to save Tsubaki Yayoi with the power of the Azure. She no longer possesses the same cold, destructive personality she had after her initial awakening, retaining Noel's personality and memories instead.
According to Relius the Mu part of Noel had split up becoming her own identity. After fighting Izanami, Mu is now searching for Noel.
Act III revealed that Noel and Mu were never the same entity and Noel was in fact the original prime field inside the Master Unit who used her as a vessel.
Powers and Abilities
As with her sister units, Mu is a very deadly opponent on the battlefield. As the Kusanagi, the Godslayer, she was designed for the sole purpose of destroying the Amaterasu Unit
- Mu's crest forms the basis of BlazBlue: Continuum Shift's logo.