On one dark and silent night, the saint was lamenting the Village's fate and meditating on how to best lead the humans of Gensokyo. That is when she sensed a wave of evil power. She turned around to see the shape of a devil, silhouetted against the moon, thirsting for blood.

Recognizing each other as someone counter to their own being, without hesitation they brought out their full power in a fierce battle that continued to swing back and forth. However, while crossing blades, they developed a strange feeling of kinship. Though their positions were different, they both shared a deep love for Gensokyo. Finally, they decided to join their forces.

Alas, cruel fate would not allow such a meeting. The devil's bloodlust overtook her senses, and she sunk her fangs into the saint's neck. The saint's power flowed into the devil, and the devil's into the saint...

As their energies clashed, they both gained some really awesome power, but it came at a price... a super-duper risky curse upon them both.