Over a thousand years ago, he ruled the area around Towada until Buddhist monks led by Nansobo sealed him away at Lake Towada.
Generations later, he crossed paths with Tatsuko Kirigakure, an Iga ninja on the run. She fought him despite her injuries and lost, but something about her desperate will moved him. Instead of finishing her off, he healed her with his own blood and struck a deal: he'd forge a sword from his fang to protect her and her line, and in exchange, she'd bear his child and die at thirty.
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