Plague Doctor - Chapter 434 - Competing Reality Hypothesis

The genius pharmacist transmigrated into a pitiful farm girl’s body. Ignored by her own father, abused by her stepmother, and bullied by her stepbrothers. Her “twin” brother was given to distant relative and she went as the “extra” to live under someone else’s roof.

Luckily she possessed mad apothecary skills. Collecting herbs, plowing herb fields, formulating medicines and treating the ills, she refused to live an ordinary life as she slowly uncovered the truth of her real identify.

Inadvertently, she saved a dashing man who was in reality a big, bad wolf hiding under the skin of an innocent little puppy. He pulled out all his tricks: I have no other means to return your favor of saving my life. What say I repay you by marrying you?

- Description from Novelupdates

Chen Yan travels between worlds, ending up becoming an honorable prince in a medieval fantasy world. Yet this world was not quite as simple as he thought. Witches with magical powers abound, and fearsome wars between churches and kingdoms rage throughout the land.

Roland, a prince regarded as hopeless by his own father and assigned to the worst fief, spends his time developing a poor and backward town into a strong and modern city, while fighting against his siblings for the throne and absolute control over the kingdom. Join Roland as he befriends and allies with witches and, through fighting and even farming, pushes back invaders coming from the realm of evil.

- Description from Novelupdates

Klaus had spent his entire existence as a puppet, bound by the strings of fate. However, a miraculous turn of events granted him a fresh start. The remnants of his former constraints smoldered in the ashes of his past. Now, unshackled and determined, he resolved to forge his destiny according to his own desires. No one, not even a deity, would be spared if they dared obstruct his path. Klaus was ready to wield the sword of vengeance and carve his own fate in the annals of history.

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.