Riches and Bitches: I have a gate to an isekai and leveling-up system! - Chapter 7: Hidden Quest: Pet the Dog

Forget about moving to the other side of the world and starting over.The Apocalypse is here!As the only survivor of the Tutorial Quest in his area, Elijah awakens the Class of “Depraved Hero”, an ominous-sounding Class with a Legendary Rank!Additionally, because of the insane difficulty as well as his Clear Rank, he gains the Skills that, according to the mysterious figure that is the Administrator, he needs most.[You have Developed the Skill “Absolute Authority[A]”.][You have Developed the Skill “Slave Mark[C]”.]

Augustus Cross was a man close to his 30s with nothing to his name. People rolled their eyes at the seemingly useless man and he remained helpless even as his daughter was at the brink of death.When all hope seemed lost, the hidden dragon within him was unleashed when the seal broke accidentally as his birthmark was stained with his own blood. Knowledge of ancient arts filled his subconscious, granting him powers to cure his daughter and other incurable illnesses.A man who was once looked down by everyone is unstoppable now. What lies beyond this man with the power he now possesses?

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!

- Description from Novelupdates

Rude is a tank, known as the strongest in history. However, the Hero decided that his skills were worthless because he couldn’t do anything but take damage, and threw him out of the party. His cleric friend who trusted him followed him to the remote village that Rude was forced to return to.