Caerula Sanguis

Caerula Sanguis (カエルラ・サングウィス, Kaerura Sanguwisu?, Latin for "blue blood") is a fictional character in the Battle Angel Alita: Last Order manga by Yukito Kishiro, the sequel to Battle Angel Alita. Caerula is one of several Last Order characters adapted from fan submissions that were solicited by Kishiro from his readers for character ideas. She is based a design called “Blue” by tfng, and the color blue is a recurring theme in the various aliases she has adopted. Formerly known as Vilma Fachiri, Caerula is first introduced as the Chairman of the Stellar Nursery Society, a small faction that operates within the main asteroid belt. However, she turns out to have a much longer history and background going back more than 700 years that parallel the creation of the current world within which the Battle Angel Alita universe is set, but was not revealed in the original manga series. As one reviewer notes, "in a very real sense Caerula's story is also the foundation of the present...her actions in the past played an instrumental role in bringing about the state of affairs that exists in Alita's current time."

Caerula is the last surviving Type-V mutant or "Cognate" as they refer to themselves as, a human who was infected by a retrovirus known as the V-virus, giving her vampire-like characteristics such as eternal youth. As a result of abilities that she has developed as a Type-V mutant, she is a formidable martial artist able to fully contend with cyborg opponents such as Alita, the series protagonist, even though she is still fully flesh and blood. Caerula is the protagonist of Battle Angel Alita: Last Order volume 9 (titled Angel's Duty by Viz Media), in which Alita does not appear once, making it the only volume thus far in both manga series to have this distinction.