The entirety of "The Reluctant Pikachu and the Exasperated Barrierd".
I know I said I didn't hate this episode at first but having recently rewatched it, Jesus I really do hate it now, it's gonna be right up there in the worst Journeys episode list. Obviously Pikachu acting OOC was bad enough but the thing that utterly kills this bird dead with two stones is that Ash is a brain-dead idiot... like so utterly thick for not even bothering to let Pikachu train with Riolu. And it's even worse because the last episode had... you guessed it... Pikachu helping Riolu out with training so it makes him look like a total farce of a trainer you wouldn't want to hang out with or root for and I can't even blame Pikachu for this. If anything, I bet Riolu must have been just as confused as we are watching these events.
And the cherry on top of this ****-cake is that apparently according to Koharu, Ash doesn't understand Pikachu.
Lemme rephrase that again...
Ash Ketchum
doesn't understand Pikachu
the very first Pokemon he ever got and has been a true friend and partner
for many years
Do you realize how utterly stupid and frustrating this sounds? Look, I'm all for giving Koharu something to do as well but this was just silly beyond all belief and you gotta love the fact that this only contradicts the season itself and the episode where Ash said that Gou wasn't in sync with Scorbunny which only makes it more ironic.
The cute moments between Delia and Ash and Pikachu singing at the end were still as adorable as ever (I'm a sucker for these little Ash and Pikachu moments), it's just a crying shame that those moments are stuck in this utter, utter
embarrassment of an episode that feels like it was written by someone who just hates these characters and went out of their way to make them look bad.
It would have stung less had this been done in say, the XYZ series but rewatching it now makes me so sad and frustrated, and that's something you never want to feel when watching a Pokemon episode.