Return of The 8th Class Mage - Chapter 143

As a man who had lived for 20 something years and had always considered himself as a straight man, he woke up one day and found himself possessed by a stupid and cute system. Moreover, it was a gong-shou cultivating system?! Let’s see how a shou with raised hackles evolves into a (pseudo)queen shou, incidentally with a story of a hidden loyal dog gong.

- Description from Novelupdates

Arthur was a weak and cowardly boy who lacked the power to protect anyone—a truth brutally demonstrated when his parents were massacred while defending him during a Gate outbreak. As the sole survivor, Arthur spent weeks believing his life was over. When intense chest pains began, he assumed he'd been infected with corruption by the void creature that killed his parents and was merely waiting for death.What Arthur didn't expect was that these sensations actually signaled his Realm Core forming. In two months' time, he would be forcefully transported to the next realm and awaken new powers, becoming one of the world-renowned “Chosen” who protect humanity from Gate outbreaks. Now Arthur must rise through the heights of power, climbing each of the seven realms in hopes of saving his world... or does he?

In a magical medieval world, it's difficult to hold on to one's beliefs... even maintaining one's integrity is a challenge.Because the commoners here are not simple; they are ignorant, greedy, and cruel.Because the nobles here are not noble; they are insidious, ruthless, and tyrannical.However... not all human constitutions can be generalized.Lann touches the two hearts and three lungs beneath his chest.He estimates that not only in this world but also in the other worlds connected through the convergence of celestial spheres, he can maintain a healthy sense of morality.—And then get rid of all the incorrigible scum!

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.