Lune is Allegra Battle Angel's newest and only friend. After her near-death experience and subsequent upgrades, Lune became her sparing partner so she could acclimate to hew newly acquired cybernetic upgrades. Thanks to Lune, Allegra has combined her martial arts skills with her one-punch robotic arm to become one of the arena's best.
Although Allegra would never tell Lune this, he reminds Allegra of her long-gone friend Nick Bluetooth. Lune's black armor would be indicative of a Gorm-sympathizer, but that couldn't be farther from the truth. His dream is to defeat Gorm in honorable combat.