What is the creative process of a cultivation novel?

I'm an aspiring writer and these cultivation novels interest me a lot. I keep imagining what the process of creating these stories is, an absurdly large world (can you imagine it when you read it?), beings that are billions of years old and philosophy, calm down, there are still mystical beasts!

I'm Brazilian and I wanted to understand how I make a story like King of Gods, Renegade Immortal or Stellar Transformations for example.

I think it would be impossible for me to write a xianxia, ​​but I wanted to do something with a lot of xianxia elements.

Anyway, I think I got off topic, how do authors create these works? Is there any guide out there?