I'm going to randomly speculate what this episode is about and what happens and what not, just to kill some time.
Ash, Iris, and Cilan are on their way to Nimbasa city when they come across a Roggenrola in the forest rampaging. Seeing this, Ash makes an attempt to capture it. Ash sends out Oshawott to battle it. Oshawott uses it's Aqua Jet but Roggenrola counters with a Flash Cannon, knocking Oshawott out with one hit. Roggenrola tries to escape but Ash sends out Snivy before it can get away. Snivy uses Leaf Storm, but like Oshawott it's knocked out with one hit by Flash Cannon. Ash then sends out Swadloon, and again it's knocked out with one hit by Flash Cannon. Ash tries to send out another Pokemon but Roggenrola gets away. Ash is about to chase after it but Cilan suggests they stop at a Pokemon Center to heal Ash's Pokemon and to have a little break, Ash agrees.
At the Pokemon Center it's busy. Iris asks some people about what's going on, and they say it's Roggenrola. They explain how lots of trainers have tried to capture it but it's too strong. Some person appears and explains more about Roggenrola. He/she explains how Roggenrola's Flash Cannon is too powerful for it to control on it's own. Explaining further, he/she says how Roggenrola is afraid of someone being it's training since it may hurt it's trainer by accident due to the out of control Flash Cannon. Hearing this Ash seems more pumped up to catch it, saying he'll find Roggenrola and help it control Flash Cannon, then they can battle again and Ash can catch it. Ash leaves all his Pokemon behind to rest and only Pikachu goes with him. Iris and Cilan stay behind to help Nurse Joy with the busy situation.
Ash and Pikachu go looking for Roggenrola and find it. Roggenrola is getting ready to fire Flash Cannon but Ash tells it he wants to help. After enough convincing Roggenrola allows Ash to help it.
*Cue training montage*. Ash and Pikachu set up all different sorts of training methods for Roggenrola, at one point Roggenrola loses control and hits Ash, Ash tells it not to worry and smiles at Roggenrola, you can tell it's warming up to Ash now.
With all that training it still hasn't learned to control it's powers fully, but it's better then before. Just then an explosion happens. Roggenrola is taken away. Team Rocket is behind it. Ash tells Team Rocket to give it back but they clearly don't listen and fly off. Roggenrola is scared. Ash and Pikachu go chasing after them.
Team Rocket say that this Roggenrola would be perfect for Team Rocket. It's massive power once control will be very useful. Ash appears and has Pikachu take down Team Rocket's flying mecha. Woobat and Yamask are sent out, Pikachu goes up against them. Roggenrola still locked up sees Ash trying to help it and seems shocked. During the battle Roggenrola gets freed. It fires it's Flash Cannon at Team Rocket with full control. Team Rocket blast off via rocker packs again.
Ash makes sure Roggenrola is ok. Then they either battle and Ash catches it or Roggenrola just lets Ash catch it. Ash then makes his way back to the Pokemon Center.
The Pokemon Center isn't busy anymore and all of Ash's Pokemon are doing fine. He talks to Juniper via picture phone, Roggenrola is there. Ash then switches a Pokemon for it or just leaves it at Juniper's for now.
Narrator concludes the episode.
