One of Xiang Yu's clones was planting herbs in the genuine world.
As he worked, he realized that he had yet to come up with a name for the genuine world. It felt strange to keep referring to it as such, so he needed to think of something better.
When he eventually reincarnated his clones into this world, he would split the world into six continents and isolate them using his power so the clones wouldn't interfere with each other's development. It would be a real shame if one clone hogged all the resources, after all.
He decided to call each of these split continents "heavens."
As for the world itself, "From now on, it'll be the Realm of Six Heavens." It wasn't really all that creative, but it should work for now.
After his keeper profession's breakthrough to celestial grade, Xiang Yu had already upgraded his series herbs like the Dreamwalker and Chrysalis. Now they even had celestial grade variants, meaning he could now advance someone's spiritual root to the celestial realm.
