I Became Beautiful by Sacrificing My Beloved

Morimori Natsuki was ugly.

She was burned across half her face while saving her childhood friend, Inumaki Toge.

Insecure Natsuki turned to cursed spirits and became a cruel demon in the dead of night, all to get her looks back.

Until...

Just as she was about to fall into the abyss,

a white-haired boy stuck out his snake-marked tongue. Blood poured from his mouth as he clutched her hand and rasped over and over, "Tsukitsuki is the prettiest girl in the world. Tsukitsuki will definitely be happy."

During the Warring States period,

the most beautiful princess of the Kannagi family transformed at night into a demon that ate people's hearts.

To preserve the most beautiful face in the world, the princess bewitched the Dog General of the Western Lands and made him willingly offer up his heart.

Amid the blood, the princess held that heart in her hands, a bewitching flower taking root in the heart of the head of the Gojo exorcist family, intent on draining his blood.

From then on,

the Gojo family had an unspeakable "taboo," and for the sake of that "taboo," the head of the Gojo family became the most terrifying "cursed spirit."

[An AU with omegaverse elements. Natsuki is the only omega.]

Elements to be decided. I'll add whatever comes to mind.

Theme: Seeking purity through unity of heart and soul.