Delta/Chronology

Unhappy Childhood
Delta was once a Beastkin Wolf girl named Sara who was one of the chieftain's daughters in her tribe and she had over a hundred of half-siblings from her father with twenty of his concubines. However, Sara did not expect much from her tribesmen because she was born from one of chieftain's lower-ranking concubines and was given meager portions of food which left her always emaciated and hungry, until her tribe finally stopped feeding her altogether when she turned three.

At that early age, Sara intends to make her own hunt into the forest and manages to kill a wild boar twice her size by hitting its skull, then she drinks its blood and eats its organs greedily. It was at that moment that Sara then realized that she could not only support herself with her two hands but did so effortlessly until Sara learned the meaning of a beastkin's life if it hunted its own prey and that the prey was precious to those who devoured it.

When Sara returned to her village drenched in the blood of her prey, all her tribesmen were shocked to witness her exploits that it was not normal for a three-year-old girl to kill a wild boar by herself, even among therianthropes so they started spreading the word. Since then, Sara has been practicing continuously until her senses and physical strength have increased tremendously and she can even use magic even though she has never had formal training.

Later on, when Sara realizes that her physical body that was once malnourished which looks like nothing more than skin and bones has already grown so rapidly that even her siblings are afraid of her strength, if for example a child her age asks Sara to fight, she will beat them in one punch and Sara will go out to hunt for her own food whenever she feels hungry. Due to frequent grueling training and constantly eating from her own prey, Sara's body quickly filled up and before long, she grew into a young girl with beautiful appearance and supple muscles.

By the time she turned twelve years old, Sara is recognized to be the chieftain's strongest daughter in her tribe because no one in the tribe could match her and the only person who could beat Sara was her father who was the chieftain. In fact, all members of her tribe made sure that Sara would probably surpass the chieftain quickly, even her own father would have given her the position of the next chieftain if she wasn't born a girl.

However, Sara has developed a disease symptom known as Demon Possession and due to the ironclad rule to all Beastkin that those who got "possession" had to be driven from their tribe without exception. After learning that Sara has possessed symptom, which was considered as filth for the beastkin, her father intended to expel Sara from the tribe and attempted to hunt her down to death because of his duties as the chieftain. But Sara successfully hid and escape from her father's pursuit.

After fleeing from her tribe with her disease-ridden body, Sara began hunting throughout the forest and prowling aimlessly. Consequently, Sara feels fine and less disturbed after she is kicked out of the tribe as long as she can continue living and hunting. However, the symptoms of the disease were eating away at her body and gradually she became so weak that it became impossible for her to hunt.

Even though her body was already reached at its limit due to feeling powerless by the Demon Possession, Sara still continued to rise to be able to hunt thanks to her incredible willpower to be able to stay conscious in her current state. It was then that Sara saw Alpha intending to help her and without hearing what she said, she immediately attacked Alpha even in her weakened state. As Sara is constantly attacking Alpha, she then seeks assistance from Shadow to deal with the situation.

Just as Sara saw Shadow, she instinctively submitted when she realized how powerful and dangerous, he was. Shadow offered to heal her and give her a home, to which Sara readily accepted seeing Shadow and Alpha as her new pack leaders, and Shadow named her Delta soon after.

First Assault on the Cult
Delta and the "Seven Shadows" assaulted the hideout of Viscount Grease in order to rescue Claire Kagenou, and Delta joined her sisters as they killed all the guards under the Viscount's command. After Shadow eliminated Grease, they rescued Claire and return home, but had her escape on her own to hide their involvement at the time. Delta would leave with the Seven Shadows to hunt down the Cult of Diablos, spending a couple of ensuing years building Shadow Garden's network.

Princess Alexia's Kidnapping
Hearing that Cid Kagenou has been accused of kidnapping the Second Princess Alexia Midgar, Delta rushes to the capital because she really misses meeting Cid. Learning that Princess Alexia was kidnapped by the Cult of Diablos, Delta takes part in a rescue mission as she leads the vanguard to ambush the Cult's secret facility bases on Fenrir's Sect Faction as the signal to start the entire operation.

After Alpha orders Shadow Garden members stationed in Midgar Kingdom including Delta to commence their raid, she strikes on all known hideouts of their enemies in the capital. At one of these locations, Delta savagely slew all Cult members and split the building in two.

Sanctuary Infiltration
Delta is part of the investigative team that took part in the operation to infiltrate the Sanctuary at Lindwurm. Seeing that Cid Kagenou had won the duel on the "Goddess's Trial" after defeating the Witch of Calamity Aurora, Delta and the Shadow Garden members prepared to enter the Sanctuary after receiving a signal from Beta disguised as Natsume Kafka.

While inside, Delta saw the dark history of the past covered by the Cult of Diablos through Hero Olivier's memories about the truth behind the Three Heroes and Demon Possession along with the Shadow Garden team, as well as Princess Alexia Midgar and Rose Oriana who unexpectedly followed them, whilst she also detained Acting Archbishop Nelson and watched his behaviors. Even Delta also learns about the Cult's origins and true purpose was to create Tears of Diablos until Alpha reveal Nelson's connection with the Cult as the 11th Seat of the Knight of Rounds. The moment when Nelson reveals his true identity, Delta attacks him suddenly. However, her attacks were ineffective to the point where she was brought by him into the Sanctuary defense system along with Alpha.

Later, Delta then battle Nelson who uses his powers to send an army of clones of himself to finish off Shadow Garden, but she easily slaughters many of them until the defense system breaks. At the time when Delta is still ready to fight after Nelson summoned Olivier, Alpha ordered her to withdraw once Epsilon with the investigation team she led already obtained all the necessary information then escapes from the Sanctuary until eventually return to the normal world.

In the anime, upon returning outside and witnessing Shadow's destructible power to annihilate the Sanctuary, Delta hadn't returned yet following the mission and Shadow Garden were guessing that Delta is still in the Sacred Land. But they decide to leave Delta be as she will come back when it starts to get cold.

Great Trading Company Conflict
Ordered by Alpha, Delta is tasked with eliminating any enforcer of private troop sent by Garter from the Great Commerce Alliance that are trying to sabotage the Mitsugoshi Company's supply chain by attacking the carriage that carrying their merchandise. In the midst of carrying out her mission, Delta reunites with Cid Kagenou in the royal capital and excitedly hugs him to his dismay. Then when Cid asked what she was doing in the capital, Delta answered her daily routine and said that she had an assignment to hunt bandits outside the capital. Delta tries to get Cid to go bandit hunting together, which he agrees having not done bandit hunting in a while. However, they will do it tomorrow because Cid has to return to the dormitory and then orders Delta to meet Alpha in taking care of business in the capital and come to Cid's room who will be waiting for him in the dormitory inconspicuously which she complies.

On the night of the next day, Delta, along with Cid who was behind her, was conducting a search throughout the forest to track down the bandit's base with Delta's sense of smell. When Delta found the smell, she moved quickly to the location where the bandits were and didn't want to wait long, Delta immediately finished off almost all the bandits who were a enforcer group led by one of the Clovers members to attack Mitsugoshi's carriage later. When she wanted to finish off the last bandit begging for his life by launching her sword at his neck, Delta stopped her actions as soon as she smelled the scent of the bandit until he said her real name, 'Sara' who turned out that the bandit was Delta's older brother even she herself didn't remember him at all though he smells like his father.

Despite their unfortunate reunion, Delta is very unhappy when he tries to beg Delta to let him live just because he is her brother by telling him that she had no "weakling" as her brother, even wanting to tell their father to take Delta back home even though Delta tells him that she can do it herself. When he tries to introduce Delta his master that he been working for "Legendary Great Wolf" Gettan, Delta didn't know about him which surprised him that Gettan is the strongest swordsman in all the wolf clans that even Delta's own father whose strength Delta couldn't beat back then couldn't defeat him either. As her brother tried suggesting her to become one of his lovers, Delta ruthlessly executed her older brother without hesitation.

In her second meeting with her master, Cid orders her to help eliminate Juggernaut of the Black Tower at the Lawless City. She succeeds, presumably cutting off his head and returns to Shadow Garden who were ecstatic to see her, believing that she had been killed. After the Great Commerce Alliance fell and Mitsugoshi Co. position become more powerful in the kingdom's capital, Delta was last seen helping Cid dig through the snow. Delta discovers something but Cid left before she could tell him.