Burning Trinity

Utsuho Reiuji is a Hell raven who acts as a vessel for the bunrei of Yatagarasu, the sun goddess's envoy. She gathered everyone together to see if the rumors were true!

Patchouli Knowledge is a witch of indeterminable age who resides in the Scarlet Devil Mansion. Ever seeking magical knowledge, she can wield the magic of the sun, the moon, and the five elements (earth, water, fire, wood, and metal). Apparently, she agreed to participate in this experiment to further her research.

Sunny Milk is one of the Three Fairies of Light, with the others being Luna Child and Star Sapphire. Her ability to refract light comes from her being a fairy that embodies sunlight. She agreed to help because she thought it sounded fun.

After hearing a rumor that combination attacks are super cool, Utsuho flew around looking for people she could team up with―people who could harness the power of the Sun like her, either through magic or some kind of special ability. Having found Patchouli and Sunny Milk, the three of them focused their energy through their outstretched hands to try out a combination attack of their own...

"One plus one plus one equals three, but..."
"One times one times one equals... one. Huh?! That's even less!"
"Stop playing around and focus."

Even though they all gathered for different reasons―one to sate her curiosity, one for research, and one for fun―their thoughts and feelings culminated into a single orb of light. This ball of devastating energy soared across the sky as soon as it escaped their control. Later on, a certain crow tengu reported that, at this moment, there were two suns shining down on Gensokyo.