I, Lu Mingfei, Accidentally Entered the Holy Grail War but Was Not the Protagonist.

I, Lu Mingfei, went through five levels and killed six generals. After a lot of hardships, I finally passed the Dragon Clan. How can I say that I am the World Tree? The author guessed that I have the ability to travel through time and space? Of course that means going back in time and changing the world line! But it seems that I haven't found the answer yet, and I ended up entering a world called Fate, where a Holy Grail War was held that was also different from the original world line. And I happened to be involved in this war, but this time I didn't want to be the protagonist. Whoever is worthy should be the one. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.