The Strongest Immortal in the City

I can't understand what's written in the back. It seems like I went to another world when I entered the secret realm? Then there was the experience in another world, and there was no explanation of returning to the real world, and the ending was rushed.

If you can suggest that the words at the end of the chapter should not be written at the beginning of the chapter. If the words are not clear enough, a little bit will do, but it looks boring.