Hope you continue this

A nice start, I can't wait to read what happens next.

interesting I can't wait to read the next chapter

That was nice to be read. There may have been some grammatical mistakes but I am too tired to think about it. Still, this is very nice.
If this take place during Pokemon Sun, but Kukui and Burnet had already have a son, wouldn't that make them around thirty to forty along with Guzma? Not that it matters but here's an advice. While it is not wrong to make your OC related to an important character, you need to try to differentiate them.
Don't make Helios better than Kukui nor Burnet. For example, since Kukui posses a very high durability and talent in wrestling, you can't just make Helios the same. Maybe his is half of his dad?
Try to make Helios unique. Give him something Kukui don't have. Like a shirt! Yeah, that'll work (Just kidding, maybe some other talents like a master of masquerade)
Just trying to help.