Legretta the Quick formerly known as Giselle Oslo is one of the God Generals and also their adjutant commander. She is Commander of the 4th division within the Oracle Knights.
Before the events of the story, Legretta's older brother, Marcel Oslo, who admired Van, died in the Battle of Northern Chesedonia in N.D. 2015. Sometime later that year, Van became Commandant of the Oracle Knights, and Legretta investigated the Closed Score only to discover that Van sent his troops to fight, knowing they would lose. She attempted to kill him out of hatred, but seeing that she rejected the Score, Van promoted her to his personal aide. She then changed her name from Giselle to Legretta.
The next year, in N.D. 2016, Tear was taught by Legretta, who followed the Oracle Military Academy's program, which lasted about six months. During this training, Tear was framed by a fellow trainee named Sein for killing a pet rappig, but Legretta discovered the true culprit and cleared Tear's name. One day during practice, Legretta was nearly assassinated by the reformist faction, then began to consider making Ion leader of the reformists. Although Tear was first defiant toward Legretta, she came to admire her and refer to her as "Major Legretta". Upon finishing Tear's training, Legretta threw away her past and desire for vengeance against Van, truly becoming his subordinate.
Sometime after these events, but still before the events of the story, Legretta was promoted from Major to God-General. She believed in Van's ideals of rejecting the Score, which she began to feel took her brother away, as opposed to Van doing so. She despised how the Score held a firm grip on people's lives, dictating their actions and feelings, and began to wonder whether she herself was nothing more than a puppet being controlled by the same. Legretta later spoke specifically on how she refused to allow the Score control her emotions, and that the will of the people should be their own.
Over time, Legretta begins to fall in love with Van, devoting herself completely to his ambitions. She slowly loses faith in the current state of Auldrant and the people living on it, even leading a massacre at Sheridan, giving little thought to killing innocent civilians in the city. Holding firmly to Van's vision, she as well wishes to destroy the current world and create a replica one in its place, finally ending the Score's reign over human's lives, thoughts, and emotions. Legretta places her faith in Van, knowing that she would die for him if the time ever came.
The only other person in the story Legretta shows sentiment toward is Tear. Being her former instructor, she shares a close bond with Tear, usually attempting to convert her to their side whenever they ecounter. Tear adamantly refuses, claiming she does not trust her brother. Legretta is hesitant to fight Tear many times, but as the story progresses, she becomes more aggressive, as she realizes that Tear's beliefs interfere with Van's, and that converting her is futile. She fights the party a total of three times, each time granting the group a less-than-friendly greeting by firing a bullet at their feet. The first time she is fought is at the end of Deo Pass, before the party reaches Akzeriuth. Once defeated, she calls Luke fon Fabre a "reject", giving him a clue on exactly what he is, and informs Jade Curtiss about fomicry being revived. The second time she is fought on Mt. Roneal, alongside fellow God-Generals, Largo and Arietta. She again tries to convert Tear, but to no avail. When defeated, she and her two companions are hurled into the ravine of the mountain by an avalanche that was caused from the fight. The oracle trio is seemingly killed, but later revealed to be alive, rescued by Arietta's monsters. She then pursues Asch, demanding he hand over the Key of Lorelei, and upholding Van's wishes even after his apparent death. The third and final time the party fights Legretta is shortly after they arrive in Eldrant. Upon being met by her usual shot, she reveals herself and admits her desire to destroy the world plagued by the Score, even if it means creating a replica world in its place.
Legretta is defeated one last time, stating that even though Tear may think she sacrificed herself for nothing, people do not lay down their lives for nothing. She confesses her feelings for Van and his vision to Tear, claiming she died fighting for what she truly believes is right, as well as the man she loved. She dies praying for Van to reform the twisted world ruled by the Score.