The Exorcist - Chapter 25Book 8: : Before the Battle

Sano Yuji, a black company employee, is summoned to another world while finishing his work at home. His profession in the other world, a Monster Tamer, is considered a job that makes it difficult to become an adventurer. However, thanks to some slimes he met, which read several magical books, he gained magical powers and the second profession, Sage. Yuji acquired overwhelming power, but is he conscious of his strength? Blindly becoming unparalleled and strongest in the world!

In this world, orphans or just anyone without any hope for this world can apply to become a “walking target”. Their sole purpose is to be a practicing dummy for the students of the sect who train to become “Demon Hunters”. These students need “walking targets” to test their training on living, walking beings of flesh and blood.
In exchange, they will be provided with food & shelter.
Their existence value is lower than a slave, but if they manage to survive a few years they can receive a life long pension.

Xiao Han is such a “walking target”. One time he witnessed a powerful Demon Hunter disposing a demon. When the demon died, a fragment of the demon that managed to escape entered Xiao Han’s heart. No one saw that, and even Xiao Han himself only felt some discomfort for an instant.

But that thing in his heart soon gave Xiao Han visions, and the first one is of a cultivation method which allows Xiao Han to absorb damage to enhance his body. A perfect cultivation method for a “walking target”.

- Description from Novelupdates

In this world, human are in peril. 72 Obelisks suddenly appeared out of nowhere, infecting the world with Monsters. Amongst this chaos, people look for hope.

A man named Basil Pacifer is the humanity's hope. He is the strongest Mage alive at that point. Sadly, he believes in no man, and he always moves alone.

...

Basil observes the unfolding scene bitterly. He is aware of his impending doom, however he has no grudge. He has lived long enough to achieve things people can only dream about.

Looking back to his past, he realized his life is nothing more than a sad story.

Closing his eyes, he accepted his end — or so he thought.

...

”Look at me! What do you see?“

”Regrets.“

”Don't you want to undo it?“

”Tell me what the offer is.“

Thus, Basil Pacifer returned to the past, being his younger self once again. Of course, he returned back with something.

...

[Ding!]

[Guide to Omniscience is successfully merged with The Chosen One]

[Analyzing The Chosen One's mental capability...]

[Analyzation Complete!]

[Result: The Chosen One is retarded]

[Initiate Brain Configuration!]

No matter how useless the golden finger he received seems, he will reach a higher height than his last life. This time, he will completely erase any regrets he has!

Being a doctor is hard. You need to go through four years of college and four years of phd, costing eight good years of your life and a giant amount of money, but still become a normal people. What else can you do? Well, someone has an answer. With a little luck, one can easily become the peerless divine doctor better than anyone in the city!