The King: Eternal Monarch

Both MLs travels in different books (Serendipity) or dimensions (The King) and finds love at some point. Both shows have a happy ending after thinking they lost each other forever.

not so similar but both have interesting touch to Crown Prince Sohyeon (who was ahead of his time, wanted to bring modern things in Korea).
While he is ML in 3 Musketeers, In The King: Eternal Monarch. Crown Prince Sohyeon, in a parallel universe, lived on to become king. His reign would cause a chain reaction that culminated in a modern constitutional monarchy.

both drama ask question, what would be if Prince Sohyeon became King as he should be.

It is a historical fantasy drama and also has time travelling. A very underrated drama but it is bingeworthy. The ML can time travel and the chemistry between ML and FL is great as well.

Another sci-fi romance where the ML travels to another universe to find the FL who supposedly saved him from death when he was just 9-years-old. But how did she do that? Did she time travel, see his past, save him or was it someone else? A bit of a more complex story, requires patience and full attention. Organic chemistry, matured romance, amazing bromance. A mix of epic love saga with crime, mystery and thriller and sci-fi. Soundtrack and cinematography were amazing too.

- Both dramas are about kind of destiny.
- In both dramas, we see ML looking for his love in different places over the years.
- The final one:In both dramas, the couple need some time together to find out what they have in common.