Valimar is the Divine Knight piloted by Dreichels Reise Arnor during the War of the Lions. Dreichels sealed the machine in the basement of what is now known as the Old Schoolhouse behind Thors Military Academy after the war and it entered a deep slumber until Rean Schwarzer's arrival. Rean overcomes the trial and Valimar acknowledges him as its Awakener. Valimar possesses the ability to increase its power by linking with secondary contractors associated with its chosen Awakener. Together they fight to the bitter end during the Erebonian Civil War and Rivalries of the Seven.
After reawakening, Valimar discovered he lost his memories and ability to speak correctly. Alongside Rean's growth as an Awakener, Valimar slowly regained his memories and speaking abilities.
Valimar appears before Rean and his friends after they overcome the final trial in the Old Schoolhouse.
Several days later, Chancellor Giliath Osborne is shot and the Noble Alliance starts its uprising. When the Panzer Soldats of the Noble Alliance march on Trista. Although Class VII fights back, the Kestrel piloted by Scarlet is too much for them. At that moment, Valimar calls out to Rean, asking "Dost thou desire the power?" Rean responds with "Heed my call, Valimar The Ashen Knight!" In response to his voice, Valimar is activated. Rean boards Valimar and defeats Scarlet in battle.
With its core wounded from the battle against Crow and Ordine in Trista, Valimar depleted its mana to restore Rean's health, making it unable the move at the start of the game. Until Intermission: "Aboard the Pantagruel", Valimar uses mana to open Spirit Paths to transport Rean and his friends to various locations in Erebonia.
As the third faction in the civil war starts moving, Valimar is frequently summoned to participate in battle. During the climax in the Infernal Castle in Heimdallr, Valimar has its rematch against Ordine.
Similar to Rean's growth, Valimar has regained its ability to speak correctly and started to express human emotions, noticeable in his concern for Rean. Valimar is capable of linking with Rean's secondary contractors as they pilot Panzer Soldats themselves and taking these machines with him as he travels through Spirit Paths.
Due to Rean's loss of self-control, Valimar is initially unable to speak at all. Valimar manages to return to his original state thanks to Arianrhod's power. Rean and Valimar win through the Rivalries and head to the final battle in Valimar's true form.
Throughout the series, Valimar assumes different forms:
- The first form is the base and most simplest form, the one Valimar is discovered in in Trails of Cold Steel.
- The second, uncontrollable form is the one Valimar assumes after Rean loses control at the end of Trails of Cold Steel III, Finale: "For Whom the Bell Tolls". Its color resembles black.
- The second form is the one assumed when Rean regains control. Valimar regains his original ashen color. This form is characterized by the two horns on the top of Valimar's head.
- The third form is the form Valimar assumes after his victory against Zector in Sen no Kiseki IV -The End of Saga-, Act III: "Hour of the Lions ~Whereabouts of Light~". He returns to a singular horn on the top of his head and resembles his first form.
- True Valimar is the form assumed after absorbing Zector, El-Prado, Argreion, Testa-Rossa and, as kindred, Ordine. This form is characterized by its wings.
- Ultimate Valimar is the form after winning the Final Rivalry and absorbing all Divine Knights. However, it absorbed not only the Sept-Terrion of Steel's power but also the curse within, resulting in corrosion of its heart, the cockpit.
- Main article: Rean Schwarzer#Divine Knight