A Unova League Evolution! (Japanese: 決着イッシュリーグ！ピカチュウ対ルカリオ！！Isshu League Conclusion! Pikachu VS Lucario!!) is the 108th episode of the Best Wishes series, and the 765th episode of the Pokémon anime. It first aired in Japan on January 10, 2013 and in the United States on April 13, 2013.
Now that Cameron’s Riolu has evolved into Lucario in the midst of his Unova League battle with Ash and Snivy, the heat is really turning up! After evolving, Lucario’s powerful moves are even stronger than Riolu’s were, and Snivy is defeated.
Ash then calls upon Pikachu, who hasn’t fully recovered from its earlier battles. Pikachu’s power and tenacity are amazing as always, the result of the strong bond between Trainer and Pokémon, and it battles Lucario almost to a standstill. But Lucario manages one final Aura Sphere to seal Pikachu’s defeat. Ash is out of the Unova League, and Cameron moves on to the semi-finals...
...where he’s up against Virgil and Team Eevee, and Flareon’s type advantage finally overcomes the powerful Lucario! Virgil’s Eevee proves to be a fierce competitor as well, knocking out his final opponent’s Druddigon to win the Unova League!
After our heroes bid a fond farewell to their friends and rivals, we leave Ash contemplating all the wonderful adventures yet to come—and feeling more determined than ever to make his dream of becoming a Pokémon Master come true!
Ash has Snivy score a quick hit with a Leaf Blade. Recovering quickly, Lucario counters with a Force Palm that throws Snivy across the field. Bianca remarks that Lucario's Force Palm is much stronger than it was when it was just a Riolu, to which Stephan states it is because Lucario had just evolved. Ash then has Snivy use Vine Whip, but Lucario blocks the attack. Not willing to give up, Ash has Snivy keep attacking Lucario with a barrage of Vine Whips, but Lucario keeps blocking them. Seeing an opening, Cameron has Lucario grab onto Snivy's vines and use Circle Throw, slamming Snivy into the ground. As the dust clears, Snivy appears to have been knocked out. With some encouragement from Ash, she manages to get up and continue the battle. Wanting to end the battle quickly, Cameron has Lucario demonstrate his new move Aura Sphere. Snivy attempts to dodge, but the attack follows her and lands a direct hit. The attack generates an explosion that throws Snivy to the ground causing her to faint. Eliminated from the battle, Ash is left with just Pikachu.
Cilan comments that although both Trainers are left with one Pokémon each, Pikachu hasn't yet recovered from his battles with Cameron's Swanna and Samurott in the previous episode. Starting the battle, Pikachu strikes first with Quick Attack. Wanting to wrap the battle up as fast as possible, Ash has Pikachu use two additional Quick Attacks. Lucario looks like it is almost beaten so Ash orders Pikachu to go in close with Iron Tail, but Lucario manages to slide away. Jumping up, Lucario comes in from above with Force Palm, throwing Pikachu across the stage. Cameron has Lucario follow up with Aura Sphere. At the same time, Pikachu lets off an Electro Ball. The attacks collide in midair and explode, throwing both trainer's Pokémon away. Both Pokémon are able to get up, but Pikachu looks like he is struggling more.
Pausing the battle, Cameron talks with Ash, saying he feels great competing in the Vertress Conference. Ash says he feels likewise and they continue the battle. Both Pokémon run toward each other. Lucario attempts to land a Force Palm, but Pikachu jumps over Lucario and dodges the attack. Not wanting to give up, Lucario follows and grabs Pikachu, tossing Pikachu high into the air with Circle Throw. Almost cat-like, Pikachu somersaults in the air and lands lightly on his feet. Following up, Pikachu hits Lucario with a powerful Thunderbolt and goes in close to hit with a Quick Attack. Pikachu is visibly exhausted but comes back around with an Iron Tail. Cameron and Lucario are determined not to give in though and Lucario uses Copycat which turns into Iron Tail as well. The two attacks collide and release an explosion. Falling from the cloud, the two Pokémon fall and hit the ground hard. Both trainers encourage their Pokémon to be the first to get up. In the stands, his friends are also rooting for Pikachu. After the encouragement, both Pokémon rise to their feet. Ash tells Pikachu to use Electro Ball with everything he has while Cameron tells Lucario to charge up an Aura Sphere. At the same time, both trainers have their Pokémon use their attacks. The two attacks collide, but Lucario's Aura Sphere manages to push away Pikachu's Electro Ball and it hits Pikachu, ending the battle and causing Cameron to with the match, moving on to the top 4. Both trainers congratulate each other and their Pokémon.
The next day, Cameron and Virgil are battling. Cameron is left once again with only Lucario while Virgil still has three Pokémon left. Calling back his Espeon, Virgil calls out his Flareon. Cameron, not worried about typing, has Lucario go in with a Force Palm, but Flareon uses Double Team to evade the attack before using a super-effective Flamethrower, but Lucario is still able to battle. Hoping to get an idea, Cameron tries snapping his head band, but nothing comes to mind, so he just has Lucario attack with Aura Sphere. Flareon counters with Fire Blast, punching through Aura Sphere and hitting Lucario. Lucario is knocked out and Cameron loses the semifinal.
It's the final round and both trainers are down to their last Pokémon: Virgil down to his Eevee and Dino down to his Druddigon. Druddigon uses Dragon Rage, but Eevee evades the attack with Dig. Coming out of the ground, Eevee hits Druddigon with Iron Tail, throwing Druddigon to the ground. Finally, Eevee knocks out Druddigon with Trump Card, making Virgil the champion of the Vertress Conference. Meeting up by the fountain, the trainers congratulate each other on their efforts. When Davy arrive to pick Virgil up, the group says farewell to him as he flies away. Just then, Bianca runs up trying to catch Virgil, but is late and knocks Ash into the fountain. She gives everyone Casteliacones. Cameron and Lucario devour theirs and run off to train. Bianca decides to head back home.
Ash and Stephan are in the sauna discussing their plans for the future. Both trainers vow to get stronger for a rematch.
At the hotel, Cilan and Iris are packing but Ash has slipped away to go back to the stadium to reflect on his performance and what it took him to get here. The flashback ends and Ash is watching the sunrise when Cilan and Iris find him.
Cameron defeats Ash, eliminating the latter from the tournament.
Virgil defeats Cameron, advancing to the final round.
The full version of Be an Arrow! was played during the flashback scenes close to the end of the episode.
The ending of the episode is a direct callback to the ending of Friends to the End, as Ash stands in the middle of the arena and has flashbacks of his journey while the sun rises over the league torch and the full themesong plays.