I Was Mistaken as a Genius Mage in a Game - Chapter 18

Invincible fists, unrivaled hammers!

At 18, Alex Kain is whisked away to Eryndor, a game-like realm where he gains 'Skill Synthesis', a talent to fuse skills into godlike powers. Battling monsters and conquering dungeons, he builds a harem of strong women drawn to his might and charm. With the power to return to Earth bearing incredible resources, Alex faces a growing threat that endangers both worlds in this epic of adventure, romance, and ambition.

She was a peerless genius in the way of medicine, holding the Medicine King Cauldron in her hand.

Once she transmigrated, she became a lowly little medicine slave in dispensary.

Physicians made her life difficult, princesses humiliated her, even her fiancé came knocking on her door to break off the engagement?

What was that?!

However, she had the cauldron in her hand; the top-notch medicinal herb was in her hands. She stole rare and precious herbs, punished the slanderous, plotted against the petty, treated the Emperor’s sickness, and saved the Crown Prince.

Then, the imperial edict turned the medicine slave to a concubine and received endless doting. It was unbreakable. Wait… didn’t Prince Jun, who wielded great power in the imperial court, say she was a a detestable individual?

As the saying goes, the concubine was good in the way of medicine.

However…

- Description from Novelupdates

Alexander was the greatest tyrant in history. His cruel, brutal and vicious reign struck fear in his enemies and allies alike. But that all ended when he was betrayed by his own people and beheaded by his archrival. As Alexander’s consciousness faded away all he could think of is all the faults he made, how he could have avoided them, how unlucky he had been, and his wrath and unwillingness to die at the hands of the man he hated most! But unexpectedly he was given not only the answers to these questions, but also a second chance to right all his many wrongs.