Coin's Edge
A young doctor felt exhausted by the hospital environment, the pressure from patients, time constraints, and the endless cycle of studying and exams. Finally, he made a bold decision: to return to a remote village and work as a doctor there, away from all that stress.
In this monotonous life, there was only one thing that managed to ease his sadness a little. It was a small novel that a patient had given him. Unexpectedly, an unforeseen accident caused him to reincarnate as a minor character in that very novel.
“Hahaha… At last, I can escape from that dull world!”
"Now I'll use this knowledge to seize all the treasures and secrets meant for the main character... enough for me to live a peaceful and luxurious life in this world."
...
"Wait, something’s wrong."
"It seems the novel I read was just a poorly made copy of this world.”
Everything was a surprise when the knowledge he possessed turned out to be a poorly replicated, predictable version, while the real world was the complete opposite. Here, the main character was decisive, shrewd, ruthless, killing without a second thought. The side characters were constantly entangled in cycles of killing and scheming.
Not to mention, the fate of this damned world seemed to be like two sides of the same coin.