GalladeRocks
Son of a Beach
Plumeri will probably make it into the Top 16 and then lose to whoever she faces there, which I'm personally hoping will be either Suiren or Lilie. As for Guzma, I can't tell if he's going to be a top contender or a jobber who might lose against someone like Hiroki or the Hinbass fisherman.
I really don't see how Guzma wouldn't be a top contender given that his Golisopod pushed PIKACHU into a corner, including shrugging off a Z-Move like it was nothing. As far as I can tell, the only trainer here that poses as much of a potential threat as Guzma is Gladion.