Despite being born into a family famous for it's extensive military history, Klara wasn't originally raised neither to be a soldier nor a pilot, instead being raised to be a perfect noble, being taught everything she needed to thrive in Ruviyane's society by the best tutors. In the beginning, her sharp, cunning mind and how easily she could manipulate others made her father immediately think she had all the right talents to thrive in role he had chosen for her. Due to that and the fact that Klara was the youngest daughter, not having a claim to the title of family head like her elder brother and the only woman of the family after her mother died a few years after her birth she had little choice in the role she would perform in the family. After all, the family needed a woman to marry into other powerful families and forge connections to other families to further expand their influence.
Surprisingly enough, as Klara grew, she began showing an increased interest towards a military career, particularly towards the huge battle-frames the knights piloted. Both the tales of her father's feats on the battlefield and the few times she was invited to watch her older brother in the training battle-frame slowly made her drift away from the role her parents had set for her, until her interest was solely focused on a possible military career as a pilot. It was only after a considerable effort and insistence from her part that her parents gave in and allowed her to enroll into the military academy, under the condition that she should have satisfactory results or go continue focusing her teaching on the ways of the high-nobility, economy and politics. At first, neither her family nor the instructors believed she would be able to do anything other than being an officer on the intelligence department, which required only intellect instead of physical prowess. After all, there was no way a delicate noble lady like Klara was fit for the military.
In the first few months of military academy, Klara was able to surprise everyone with how well she was able to perform under pressure and deal with the harsh training. Despite her small body, she was fast and agile on her feet and most importantly, had an unusually sharp and quick mind, even when under pressure. As the first sparring sessions in battle-frame simulator began, all the remaining doubts regarding Klara were immediately cleared, both by her family and the instructors. Whenever Klara was in a combat situation, even if it was a simulated one, she turned into a completely different person. The unbelievable ferocity, efficiency and ruthlessness she displayed, even on trainings was enough to quickly overwhelm and knock down all the other cadets and give even a few of the instructors a hard time, despite her preference towards using melee weapons.
Thanks to her performance, Klara graduated from the Military Academy quite early, with only 17 years, being assigned into the same armored division her older brother and father were. Even as a beginner pilot, her ferocity on the battlefield quickly made her known as a very promising talent. Performing better than some experienced pilots despite using only a stock Lancer frame, Klara's contribution only grew as the battles continued, as it did her infamy due to her cruel fighting style and the seeming excitement she felt when in combat. The blood curdling giggles, laughter and humming that could be heard from the radio as she mercilessly pierced enemy battle-frames with her Lancer and broke their formation, despite being unnerving, was enough to boost the morale of ally pilots and soldiers.
Unfortunately, even for such a naturally talented pilot such as Klara, there was only so much she was able to do with a stock Lancer frame. Especially given the fact that her unique fighting style didn't really match the frame. In one of the combats, the poor match of her frame with her combat style finally caused an incident when she was unable to dodge out of the way from an explosive shell from an enemy long-range battle-frame, which exploded just before piercing her frame. The pressure from the explosion was enough to immediately send her unconscious, even before she noticed that shrapnel fragments from her own battle-frame's armor cut both of her arms. Fortunately, she was quickly rescued by her allies and immediately sent to a hospital. Due to the strong shock of the explosion, Klara would end up waking up only a few weeks later, already having her arms replaced by highly advanced, custom made cybernetic arms, provided both by the army and her family.
Even though Klara didn't receive any psychological trauma for seeing her own arms being torn to shreds, due to being unconscious, the rehabilitation still took a decent time, including getting used to her new arms. At first, when Klara stated her intention to go back to the military to her family, there were some protests, but they were quickly silenced by her father, a hardened veteran which stated that not only it was right for her to go back to the military, but it was her only choice, as she had chosen the military career herself. Regardless of her father's rough words, which were in part expected, given how famous he was for not being exactly someone to openly show his feelings, it was still evident that she had his support, especially with her receiving from him, a modified Lancer frame, including an upgraded heat lance and focusing more on agility instead of armor.
Armed with a modified frame and her new cybernetic arms, Klara's return to the battlefield was nothing short of terrifying for the enemy. With a frame that was able to keep up with her quick thinking and move itself in the way she wanted, Klara's contribution on the battlefield, was enough to rise her status from a mere pilot to an ace. The quick, lightning offensives commanded by her father and led by her brother had an immense success whenever she was included on them, always followed by devastating losses for the enemies. The battles after her return to the battlefield were the ones responsible for giving her the nickname 'Sanngridr'.
Unfortunately, despite the many years of service her family had dedicated to the empire and even hers and her brother's achievements in combat, something neither Klara herself nor her family was expecting. While neither one of them were oblivious to the tactics the empire used, which saw both equipment, pilots and soldiers as mere 'numbers', willing to abandon an entire platoon if the loss of units and resources was considered to be acceptable when taking in consideration the result, they had never expected such fate would befall them instead of mere low-ranking, volunteer soldiers...
Despite the repeated successes in the quick offensives Klara's division had recently, on that particular day, they encountered an unexpected resistance from the enemy. The initial plan was to quickly infiltrate behind enemy lines and attack a convoy of transportation units before they reached the front-lines carrying ammunition and resources. According to the data they received from scouts and surveillance, the convoy should have been escorted only by a few enemy battle-frames and in the beginning, everything was going on according to the plan. But on the very moment they made their attack on the convoy, the transport vehicle opened up, revealing another unit of battle-frames, ready for combat. Being quickly surrounded, Klara's unit did her best to retreat, but having been caught off-guard by the reinforcements, there was little they could do but to ask for support, which according to the report they received from the headquarters, would take a few minutes to arrive.
Despite the numerical disadvantage, Klara, her father, her brother and their unit continued slowly retreating while waiting for the promised reinforcements. Focusing only on maintaining a tight formation and avoid being flanked, they continued slowly retreating, but for every two enemy battle-frames that they damaged and incapacitated, one of theirs was completely destroyed. This grinding battle continued until there was only Klara, her brother and her father remaining. At that moment, a radio transmission was received on their radio. Relief was clear in their expression, believing the reinforcements had finally arrived. Much for their dismay though, instead of the contact from friendly units and battle-frames, they received a single message...
"Klara Weiss, Alexander Weiss and Maximilian Weiss, thank you for your years of service for the empire. May the emperor's grace be with you."
The moment they finally understood the meaning of that message, it was already too late as the artillery shells began bombarding their position, immediately annihilating both the enemy battle-frames and theirs at the same time. The empire had decided that mobilizing an entire unit as an emergency measure to enter in direct combat with the enemy forces and rescue their unit was simply too much of a waste of resources to rescue them, so instead of ending that confrontation in a total loss, they calculated it would be more beneficial to send long range artillery to bombard their position as there would be much bigger losses for the enemies than for the empire themselves. The last thing Klara remembers was the deafening explosions as the shells impacted the ground, before her battle-frame was almost tackled by her father, Maximilian and her brother Alexander...
Klara woke up hours later with the alarms of her custom Lancer unit exploding into her ear. The cockpit, albeit cracked and damaged, was still functional and the upper limbs seemed to have retained at least part of their movement, but the lower part of her battle-frame was completely gone, exploded to bits due to the bombardment. The moment she turned on the monitor again, much to her own despair, she could clearly see the reason for her survival... Above her own battle-frame, there were the contorted remains of her father and her brother's frames, having shielded her before the explosions. Enraged, Klara got out from under the scraps of her former family, dragging her broken battle-frame back towards the front-lines. During that time, there was only one thing in her mind... She wanted to know why... Who was responsible for such decision. After all the years her family dedicated to the empire and they still treated them like mere numbers.
Before she could reach her destiny though, she was stopped by a squadron of scout frames from the enemy forces, searching for survivals in the smoking crater that was once the place where the ambush convoy was. Unarmed, exhausted and with a broken frame, there was little Klara could do but to surrender herself... Oblivious to the events that led to her capture, she was considered a high-profile prisoner, due both to her status as a noble and her achievements as a pilot. It was only during her time captured that they came to know about what really happened and made Klara an offer... If she volunteered to fight for them in the Phantom Brigade and agreed with their conditions, they would not only give her a chance at revenge, but they would also consider give her political asylum and protect her, should the empire come after her after considering her a traitor. For Klara, the answer to such proposal was an easy one. Not only she would be able to go back to the battlefield, she would have a chance to get revenge on those who betrayed her.