Jitsu wa Ore, Saikyou deshita? ~ Tensei Chokugo wa Donzoko Sutāto, Demo Ban'nō Mahō de Gyakuten Jinsei o Jōshō-chū! - Chapter 87: What’s happening?

A story about a traveler who crossed into a parallel universe, relying on his Proficiency ability to continuously grind experience and become stronger.

A young man with an extraordinary mind is off on an exciting adventure when he mysteriously wakes up in the body of a feeble slave-guy in a different, rich in quirks world.

The main character, a selfish jerk, would use extreme means to achieve his goals. However, he never allows his base instincts to overrule his sense of decency. He always pays back both good and bad deeds.

Will his (terrible/excellent) mentality help him make a fresh start? Will he get through misfortunes and hardships of the new world?

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

We are born free; yet, why do the deities and Buddhas claim supremacy!Bodhisattva, Buddha, Deity? ... I shall wipe out all your Divine Souls!If the heavens obstruct me, I will shatter these heavens; if the earth obstructs me, I will crush this earth!Tathagata, today you must return to me—five hundred years!...