Well it seems as if he's losing a lot for the sake of the plot. :/
Darmanitan:Bianca's dad's Pokemon since childhood, meaningless struggle from the start.
Hydreigon:Fully-evolved Dragon
Pansear:Crappy win for Chili, Oshawott should have blocked that Solar Beam with his scalchop sitting in his hand. He didn't win just to give Chili a win and make him look good, seems weird they just didn't have Pansear knock out Pansage if they wanted to make it look good.
Herdier:Make Cheren look good.
As long as the plot isn't working against him, he's shown to be a good battler. Knocked out Timburr easily, beat Clay's Krokorok, Cilan's Pansage, trained and learned to open his eyes open under water and one-shotted Palpitoad, trained to learn to not use his scalchop or rely on it heavily and beat Stephan's Blitzle.
For example Excadrill, Stunfisk, and Pikachu had no chance from the start against the Kami Trio because Landorus had to solve the problem on its own. When he isn't being used as comedic fodder, like against Herdier or Roggenrola, he's quite strong. He's in need of evolution right now mainly.