Silver Shadows - A Vampire Knight x Black Butler Fanfiction

Three decades had passed since the tragic death of Ciel Phantomhive, leaving Sebastian Michaelis unexpectedly stranded in the human realm, bound by mysterious circumstances. As time wore on, Sebastian wandered through a world that had long lost its allure, his purpose unclear and his once unshakable resolve fading.
It was during this period of aimlessness that Kaien Cross, the wise and enigmatic headmaster of Cross Academy, discovered Sebastian. Sensing the demon's immense knowledge and potential, Kaien extended an unusual offer: to become a teacher at his prestigious night school, where vampires learned to navigate the complexities of coexistence with humans.
Accepting this new role, Sebastian became an integral part of the academy's nocturnal world, his dark charm and sharp intellect captivating the students. Among them were two seemingly ordinary young adults, Zero and Seraphina, who had been raised alongside Yuki Cross. However, only Kaien knew the truth: Zero and Seraphina were not human. The secret was carefully guarded, even from Sebastian, and to complicate matters further, Seraphina herself was unaware of her true nature.