- Chapter 1
Lena was asked by her superior and her late father's close friend—Jérôme Karlstahl—to take command of the elite Spearhead Squadron after the previous Handler resigned. The Spearhead Squadron was an elite unit consisting of veteran Processors assigned to the battlefields with the heaviest combat. The squadron's infamous captain—Undertaker—was rumored to be the cause of a Handler's suicide. As no other Handler would volunteer for the role, Lena would take the assignment out of a sense of duty, despite Karlstahl giving her the option to refuse.
- Chapter 2
She resonated with the Spearhead Squadron for the first time on May 22nd RY 367; while she couldn't be of help on that day's battle, her initial suggestion of where the squadron should be deployed was noted to be a competent answer by Wehrwolf. She continued to check in on the squadron nightly and engage them in conversation. While Lena genuinely saw these nightly Para-RAID synchs as her way of humanizing the Processors, the members of the Spearhead Squadron saw it as a way to kill time, merely superficial niceties.
- Chapter 3
With the intention of fully supporting the Spearhead Squadron, Lena spent her time researching Legion formations and reinforcement rates, as well as finding a map of the Eastern Front's First Ward.
Relations between her and the squadron would sour after Kirschblüte's death on June 15th. She was severely berated by Laughing Fox for even thinking to give words of mourning to the squadron, as he considered that—in the heat of the moment—she did not have the right to do so as one of their oppressors. Without realizing, Lena had made Kirschblüte's death about Lena's failure, putting the focus on herself instead of their deceased comrade. She also still adheres to the prejudices implanted by the Republic subconsciously, never even considering to refer to them by anything but their Personal Names. She disconnected from the resonance once requested by Wehrwolf, after which she would have time to reflect on her world view and ideals. Even with Annette and Karlstahl's dissuasion, her conviction to help the squadron remained firm.
She nervously reconnected with Undertaker later that night, apologizing for her behavior and requesting for the names of the squadron's members. Sensing that Lena was eager to prove herself once more to the squadron, he gave her a chance and introduced his comrades' names to Lena one by one, also telling her about his promise to carry the tags of his fallen comrades. With his help, she would manage to repair their relationship and set a true foundation for their interactions moving forward. Undertaker would eventually introduce himself as Shinei Nouzen, to which Lena would ask if he was related to a Processor by the Personal Name of Dullahan—Shourei Nouzen. He confirmed that Shourei was his brother and told her of his death five years ago. He admits to Lena that he does not have any plans once he was discharged, only that his current goal was to search for his brother. Lena was confused by what he had meant, but Shin simply deflected.