It is a very strange thing.
Because, at first, it tries to be very like Solo Leveling, with a game based story, a necromancer who start having his own little army while doing things alone. Even the title itself kinda sell this idea.
But at the same time, it does nothing alike solo leveling...or even the title tries to imply. The MC is never totally alone in his operations. The game like system is for every character. And it become more of a political/world war story than the story of SL.
BUT, and this is a huge but, in itself the story isnt really interesting. Almost every new encounter is a scummy person, when they are not obviously made as a good guy. The MC isnt really interesting to follow, since he has no backstory or goal for himself. And the fight scenes, which would be very interesting to see become more expeditive and quickly made, as much that there too much talk and not enough fight. Everyone tries to be smart and outsmart the other, to the point where you just loose yourself in bullshit explanations.
Also, why does china characters are directly introduced in some kind of time twisting element that take them back to there empire era ? Did i skip a scene or something ?
Where does this story want to take us ? What is continuity of the story ? What are the rule of the universe ?
It's not mystery, it's just not really well written. It's like a game full of side quests with no main quest to tie everything together.