How is this a sequel to Coiling Dragon (Novel)? I'd love to know, are they just set in the same world or are they directly connected?

It isn't.
Coiling Dragon plays on one plane of existence in a multiverse, this is another, no characters are shared. Concepts and some lore overlap, but that is it.

thank you 🙂

Extreme spoiler for Coiling Dragon

Linley actually creates the world this story takes place in after he becomes a universe creator

close to the end of the novel the MC of coling dragon comes to qin yu and tell him to call him brother and so forth later on it is shown that he created qin yu world

thanks, guys ^^