Roku-hime wa Kami Goei ni Koi wo Suru ~Saikyou no Shugo Kishi, Tenseishite Mahou Gakuen ni Iku~

For the loyal knight Vance, duty was not a burden but the very pulse of his existence. His life was wholly dedicated to his liege, Princess Arsmeria, and when the threat of death loomed over them, he made a choice born of unwavering devotion: to reincarnate alongside her, pursuing her soul across a chasm of a thousand years. In this new era, he awakens as Lloyd, the foster son of the noble Countess Myuria, a young man blessed—or perhaps cursed—with the rare and enigmatic power of colorless magic. Though the world around him has transformed beyond recognition, his heart and his memories remain untouched, his mission as clear as it was in his previous life. His quiet existence of study and training shatters when he discovers the staggering truth of Arsmeria's rebirth. The princess's soul, once whole, has been fractured, her essence scattered and divided into six distinct fragments, each now residing in a separate individual. Lloyd is left with an overwhelming responsibility: to find each piece of his beloved liege and somehow unite them. Navigating the intricate halls of a magical academy, he must balance his duties as a student, conceal the potent truth of his past, and identify the bearers of Arsmeria's soul without revealing his own hand. Bound by a love that transcends mortality and burdened by a secret that could unravel his new life, Lloyd must master his colorless magic to overcome enemies both seen and unseen. The path to restoring his princess is a treacherous one, fraught with mystery, political machinations, and the relentless march of time, as he works tirelessly to reunite the fragments of a soul he swore to protect for all eternity.