Ultimately, I think it's going to end with Guzma vs Ash in the finals. I know that Gladion is seen as his rival, but from his character's position he doesn't really belong in that league. Isn't his goal now to find his father? I mean he did find Zoroark, unless he only wants to get stronger but I still have a hard time seeing that purpose. In my eyes Guzme definitely has a better purpose to get into the finals. He wants to destroy the league (And I'll eat my own words and say that does make him the villain) and take the moment away from Kukui, he even wants to defeat him.
I don't even know how to feel about Hau at this point.