Hail the King - Chapter 10: I’m Invincible

Corporate slave Reiji went to another world one day, made one rank higher potions, and li~ghtly made a killer profit!

He used that money to open a drug store, and troubled people who heard the rumors came over…

Eyedrops for an elf troubled over his failing bow aim!

Cough syrup for the dragon that unintentionally releases his dragon breath!

Reiji makes medicine for troubled people, enjoying his leisurely slow life in a rural city.

When an era came to an end, various forces set foot in cultivation to compete for immortality. A young boy who spent most of the time sleeping got lucky in the troubled times and became an unparalleled immortal who could cover the sky with a snap of fingers. Was he going to live forever?

- Description from Novelupdates

Our protagonist Caam is a man from Earth that was reincarnated into this world as a demon. In order to survive, he spared no effort in avoiding the sparks of battle and without noticing it, he became strong himself.

____this story sets in Japan that developed a little different history from yours.

This is how a Japanese Princess relieves her stress of the day by using the latest VRMMORPG, and while playing the villain there, the first town turns into whirlpool of chaos, smashed the underground organization in one hand and went for a coup. It’s literally a playtime diary of a girl who is called as “Genocider-san”, “Roaming Last Boss”, “A different person plays the game”, “Raid Boss”, “Ruthless”, “Calamity”, and such by the players.