The Backbender (Avatar: The Last Airbender) - Chapter 31 - : Upgrades

A Di [legitimate-born] daughter of a noble house turns into an abandoned daughter. No father to dote on her, no mother to love her, no problem. She uses one silver needle to save a dying man. What’s so unusual about a medical injection? She roams all over the world with a scalpel in her hand. Cutting throats, cutting open abdomens, cutting open skulls to mend bones. With amazing medical skills and ethics, she gathers a flock of officials, obtains the will of heavens, gains public favor, and receives Taizi’s [Crown Prince] doting. In the midst of a powerful momentum, her cheap father comes to reunite. She coldly refuses to go home or acknowledge ancestors.

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

During the first known year, a magical mountain descended into the world from the realm of the Gods. Carved on this enormous mountain was a message: ‘Heaven Prevails’…

After the Grand Descent, a name that was given to the descending of the mountain, the Three Great Sages made their ways to Mystic Mountain where they learned to harvest what we now call magic, establishing the Mystic Cults and eighty-one sacred shrines to help aid mankind with the cult’s mystic powers against the eternal fight to the death with demons.

- Description from Novelupdates

Keita Sumeragi was a man of dreams—once a hopeful mangaka who poured his soul into heartfelt tales of romance, comedy, and friendship. But the world never smiled back. Readers ignored him. Publishers laughed. And when the only offer he got was to draw the one thing he hated—NTR (Netorare)—he refused.Until life left him no choice.His wife walked out. His daughter starved. And when his first NTR manuscript was complete, the publisher gave the job to someone else.Broken, guilty, and hollow, Keita leapt from the rooftop with a bitter smile—Only to awaken in the world of his own rejected NTR manga.In this twisted realm, he’s reborn as the main protagonist—handsome, popular, and surrounded by women with all-too-familiar faces. His sweet and kind “motherly” wife resembles the wife who left him. His seductive stepsister has the same eyes as his daughter once did.In this warped erotic hell, where anyone can be seduced—teachers, aunts, even grandmothers—Keita must face his deepest guilt, his darkest fantasies, and the genre he once despised.Because in this world, NTR is fate.And the story must go on.

Synopsis is in the beginning first chapter, so you can try to read it first.Zhang Fei is an ordinary human, but he is also an Incubus, and he also a Heavenly Fox.