Culke no Yuuutsu

Lately, Kirche has been feeling anxious about how she’s been fading into the background.
One day, she stumbles upon a book containing secret techniques.
Drawn to a spell labeled “Magic to Enslave the Opposite Sex,” she chants the incantation…
But the spell backfires, transforming her into a futanari.
Staring down at her new, impressive appendage, she thinks:

“With this magnificent cock, I’ll defile the woman who stole my spotlight…!!”

And so begins Kirche’s revenge…

[Translated from dlsite]