Tejeswini:
I only watched the drama and I loved it, I have one question did he change the future or was all of it just his imagination when he was in a coma?
You can take it both ways but I want to believe everyone went into the game, but when it was purified by Ruan, things went back to how it was initially. If you ask why, that's because Jiushi could remember people he sees daily and imagine the game in his head but knowing everyone's name, remembering places, and tonnes of other things subconsciously is a kinda far stretch. How could he know the correct names and faces of a doctor, nurse, or even a random group of strangers crowding him after the accident? That's just impossible.
So maybe the world got reset once the game was over but he remembered because he promised to bring back everyone together including Ruan. But I have to say, ending and 50-year time leap was sad.