According to the prophecy in the Holy Scripture, in the year 273 of Creation, the Holy Son will descend into the world, eradicate all evil, cleanse people's souls, and usher in a new era ruled by God.
Impatient, the Great Demon King burned down the monastery and dragged out the young Saint.
The young Saint looked like a statue on the church altar, with golden hair that shimmered as if sunlight had been crushed and scattered through it. His sky-blue eyes were moist and compassionate. He wore a white robe, but... he was a boy?
After bringing the young Saint back in chains, the Great Demon King's first act was to lift his robe.
"Bear my child." The Great Demon King cruelly defiled the young Saint's skin inch by inch, baring his fangs without the slightest attempt to hide them.
"I can only bear God's child." The young Saint touched his belly, where only a thin layer of flesh covered it.
"I'll be your god."
"Then... what about the original God?"
The Great Demon King replied impatiently, "Why not just kill him?"
The young Saint nodded, wide-eyed, thinking it sounded like a perfectly good idea.
One day, the Great Demon King told the young Saint, "When you fall in love with me, I'll eat you. Then you'll only be able to love me forever, and we'll become one."
A blush spread across the young Saint's snow-white skin. He lowered his head. "Then... you can eat me now..."
Yandere Saint (noun), intersex bottom x unhinged, deranged Great Demon King top
Theme: There's no real theme. I'm not exactly a serious person, anyway.