Alchemy of Souls

Set in a fictional country called Daeho that does not exist in history or on maps, it is about the love and growth of young mages as they overcome their twisted fates due to a forbidden magic spell known as the "alchemy of souls", which allows souls to switch bodies. It follows the story of an elite assassin named Naksu, whose soul is accidentally trapped inside the weak body of Mu Deok—Jang Uk's servant from a powerful and noble mage family in the country. The young master of the Jang Family, Jang Uk, holds a dark secret about his scandalous birth. He wants the formidable assassin to help change his destiny.

Sakahira Riku, a first-year high school student, is jokingly pushed on the shoulder by his friend Tasaki while swimming by the pool, and falls into the pool with Mizumura Manami, who is next to him. The next day, when he wakes up, he finds that his body has been swapped with Manami's. Both are confused and try everything to get back to normal, but nothing works. They are forced to desperately exchange information about their families, friends, club activities, etc. in order to play the role of each other.

Set in a fictional country called Daeho that does not exist in history or on maps, it is about the love and growth of young mages as they overcome their twisted fates due to a forbidden magic spell known as the "alchemy of souls", which allows souls to switch bodies. It follows the story of an elite assassin named Naksu, whose soul is accidentally trapped inside the weak body of Mu Deok—Jang Uk's servant from a powerful and noble mage family in the country. The young master of the Jang Family, Jang Uk, holds a dark secret about his scandalous birth. He wants the formidable assassin to help change his destiny.

Both FLs are powerful and skilled in magic, and end up transferring their souls into the body of a weaker, powerless girl. The original body is burned, and then end up aiding the ML as well as being under his protection.

Although they are from different countries (one is Korean, the other Chinese), I have to say both are masterpieces. The fantasy element is what really stands out in these dramas. The acting is top-notch in both, and they share common themes such as mystery, powers, romance, friendship, strong lead characters, and humor. If you liked one, you'll undoubtedly like the other.

Alchemy of Souls reminds me of the Chinese drama Ashes of Love.
The plot is not similar, but I enjoyed watching the progression of the love between the leads. This is something you could watch in between waiting for AoS new episodes since it has many episodes (63).

A love story between the half-human and half-vampire Seon Woo Hyul, who was unable to become human due to a one-day difference over 100 years, and Joo In Hae, a woman who has no humane side and finds true warmth.

Both drama show the ML becoming powerful and mastering their swords! Both characters are witty and do their best to protect the people they love.

Set in a fictional country called Daeho that does not exist in history or on maps, it is about the love and growth of young mages as they overcome their twisted fates due to a forbidden magic spell known as the "alchemy of souls", which allows souls to switch bodies. It follows the story of an elite assassin named Naksu, whose soul is accidentally trapped inside the weak body of Mu Deok—Jang Uk's servant from a powerful and noble mage family in the country. The young master of the Jang Family, Jang Uk, holds a dark secret about his scandalous birth. He wants the formidable assassin to help change his destiny.

both of the main characters are badass in their own ways, its historical its about revenge with martial arts

Set in a fictional country called Daeho that does not exist in history or on maps, it is about the love and growth of young mages as they overcome their twisted fates due to a forbidden magic spell known as the "alchemy of souls", which allows souls to switch bodies. It follows the story of an elite assassin named Naksu, whose soul is accidentally trapped inside the weak body of Mu Deok—Jang Uk's servant from a powerful and noble mage family in the country. The young master of the Jang Family, Jang Uk, holds a dark secret about his scandalous birth. He wants the formidable assassin to help change his destiny.

In both Fake Princess and Alchemy of Souls, both the FLs work for High ranking families( in Fake Princess, for Crown Prince in Alchemy for Royal family Mages)
Similarities:-
1. Female leads are replacements to the original characters
2. Both come from a village backdrop/ country
3. Both possess fighting skills( In Fake Princess FL being a Mountain Bandit & in Alchemy FL being a Trained Assasin)
4. FLs are smarter than MLs
5.Both FLs have birth secrets
6.Both involve the FLs hiding their secret identity

Differences:-
1.Alchemy is more about magical, mystical elements (like WUXIA) while Fake Princess is a light hearted Rom-Com
2. AoS has a second ML( major SLS alert) unlike Fake Princess
3. In Fake princess, ML fights his brother for the throne unlike AoS

In both of the story the ml is weak at first and will become strongest among the mages/counters
Great teamwork and friendship+ you will get Yoo Jun-sang (park Jin) here too ?(kind of same father figure and one of the strong character, he's friend of ml's father too )
Both ml grew up without parents
Both storyline follow hunting evil soul or soul shifters and the soul shifters/evil souls feeds on human soul
TUC doesn't have much romance and more action based show and set up in modern times
Though it can't beat AOS in storyline, production and fantacy, TUC is still entertaining in its own way
Yoo In-Soo is in the 2ns season and a silly counter friend of ml
If you enjoyed AOS hope you will enjoy TUC too

In 1867, Sin Jae Hyo leads the Dongrijungsa, which teaches pansori (traditional Korean musical storytelling). A young girl, Chae Seon, who wants to perform pansori, appears in front of him. Chae Seon has dreamed of performing pansori since she first heard Sin Jae Hyo perform when she was little, but Sin Jae Hyo turns her down because women are not allowed to perform pansori. Chae Seon then disguises herself as a man and enters the Dongrijungsa to learn pansori, but Sin Jae Hyo doesn’t accept her as his student. One day, he hears Daewongun, the most powerful man in Joseon and the father of the King, is going to hold a national competition of pansori performers known as “Naksungyeon”. Sin Jae Hyo decides to teach Chae Seon, who has a true voice to perform “Chunhyangga". If anyone finds out that Chae Seon is a woman, Sin Jae Hyo and Chae Seon will both face death.

both rely on energy and sensing energy
both have a core of energy
both have a master/teacher and pupil
both about wicked spirits and destroying them