Mu-12, also known as 'The Sword of the Godslayer', is a pivotal character in the anime series BlazBlue: Alter Memory. Originally, she was the 12th Boundary Interface Prime Field Device, a prototype weapon crafted to destroy the world’s balance. Created by the sinister organization Sector Seven, she is designed as a vessel to host the Azure Grimoire. Throughout the series, Mu-12 undergoes significant development, transforming from a cold weapon into a sentient being with human emotions, primarily due to her connection with Ragna the Bloodedge. Her journey explores themes of identity, autonomy, and redemption.