As the synopsis mentioned. This is a story/journey that follows Chu SiJing to find his brother Chu SiYu who was lost to a weird happening in an island.

It’s a Chinese Sci-Fi story set in the Ming dynasty, and the war was just a forgettable backdrop with no further mentioning.
I started watching because the premise was interesting, the plot of the first few episodes have a good pace and kept me curious. So the story follows Chu SiJing to investigate the mysterious secret of the island link to his missing brothers. Many elements brought up were interestingly and can have good potential for further development if given more thoughts. E.g. monsters among human, cult group, magical powers, traditional ancient Chinese mystical creature, underlying political agenda to uncover or hide the secret, etc. Initially it gave me vibes of Kdrama, Kingdom, or the Game of throne, then came Alien under the sea.
However the final reveal was IMO anti-climatic and with an ending of a heroic sacrifice.
The ML throughout the story was in high tension state, was wondering when his blood pressure will pop. There were some interesting side characters that I felt if given more time, can have great potential to develop deeper, such as the Eunuch Yang’s agenda, the soldier Bo Yan, the sea girl Angelica, Shen Rang, Captain Xu, even the Head of JingYi Wei / special forces.
But I guess for a short drama series, it is a good attempt and straight to the point story telling, there are some good fight scenes, and genuine friendships/ kinships theme.

If you like a quick Sci-Fi drama, this is a good watch., will not recommend a re-watch.