Rough around the edges, but overall it's interesting enough to give readers a good read.
The world building could've been great, but the author gives us confusing infos, there're gods, but how many? What do you get from a convenant with a God? What kind of instrument are there? What are the effect of each instrument? The system/levels? Are some questions that might surface when you read this novel.
Character-wise they're great, the emotion of each meeting and separation could be felt easily.
Plot-wise is already good coupled with the world building.
Honestly, the lore/world is interesting if you could spare a few braincells to visualize this story as a blank paper. Just imagine the world, by each word, don't put in any visualization you might have from cultivation novels. Think of this one as a western novel.