Battling the King of the Mines! (Japanese: 地底のジム戦！VSヤーコン！！ Underground Gym Battle! VS Clay!) is the 14th episode of Pokémon: BW Rival Destinies.
Once again, the time has finally come. After being denied twice, Ash finally gets his Gym Battle with Clay since he gave him a bag of Revival Herbs he requested. As a surprise, the Gym battlefield is located underground. Will Ash be able to beat the Gym Leader who calls himself the "King of the Mines"? And what is up with Roggenrola since he begins to glow while battling his Excadrill?
The heroes come to Driftveil Gym, where a worker appears. Ash presents the sack with the Revival Herbs and follow the worker and descend down in an elevator underground. The worker claims his boss' Pokémon are quite powerful. They come to Clay and give him the Revival Herbs and he passes it to other workers. The heroes follow Clay, who presents the battlefield underground. Ash and Clay take positions, while Iris thinks this is a unique underground Gym. Clay sends Krokorok and Pikachu wants to battle, but Ash tells Pikachu he won't be effective against Ground-type Pokémon. Instead, Ash sends Oshawott.
Oshawott starts with Aqua Jet, but bashes into a wall, as Krokorok digs. Krokorok emerges and uses Sandstorm, causing Oshawott's eyes to be filled with sand. Krokorok bites him, so Oshawott uses Razor Shell, but upon getting his eyes hit by Sandstorm, Oshawott randomly misses Krokorok, who knocks him down using Stone Edge. Oshawott stands up and uses Water Gun above the field, which nullifies Sandstorm. Krokorok digs, but Oshawott uses Water Gun on the hole, foiling Clay's strategy. With Aqua Jet and Razor Shell, Oshawott defeats Krokorok. Oshawott is pleased and high fives Ash and Pikachu.
Clay calls Krokorok back and laughs, thinking Ash has spirit, even if he is a wimp. Clay sends Palpitoad. Oshawott uses Water Gun, but gets hit by Palpitoad's Hydro Pump. Oshawott uses Razor Shell, but is hit by Sludge Bomb. Oshawott lost his scalchop and while he finds it, he gets defeated by Palpitoad's Rock Smash. Clay is starting to doubt Ash has got guts. However, Ash has a plan and sends Snivy. Snivy starts with Attract, which affects Palpitoad. Snivy uses Vine Whip and Leaf Blade, which hit Palpitoad. Using Leaf Storm, Palpitoad is defeated.
Clay is furious and outraged, as he calls Palpitoad back. Clay accuses Ash of using unfair tactics. Ash claims that was his strategy, but Clay yells at him to just charge head on like a man. Clay removes his hat and sends Excadrill, admitting it is a much different Pokémon. Iris is surprised, as Excadrill is huge. Snivy uses Vine Whip, but is countered by Rapid Spin. Snivy uses Leaf Blade, but is stopped by Excadrill's Rapid Spin. Snivy tries to attract Excadrill, who spins to negate the move. Snivy uses Leaf Storm, but is deflected as well. Using Horn Drill, Excadrill defeats Snivy.
Ash calls Snivy back and is still determined to win, as he does not want to give up on his goal to become the Pokémon Master. Clay shows his pickaxe and tells he dug with Excadrill since he was Ash's age. He points out that Ash wants to become a Master already. Clay tells he dug this mine and earned the title "King of the Mines" and is here to show how tough accomplishing a goal can be. Ash decides he will prove his point by sending his last Pokémon, Roggenrola. Cilan bets Ash is counting on Roggenrolla's toughness to win this battle. Roggenrolla uses Sandstorm, engulfing the field. Excadrill uses Drill Run, which sends Roggenrolla into air.
Excadrill repeats the attacks to hit Roggenrola. Clay sees even after these attacks Roggenrola still has guts. Excadrill uses Horn Drill, which hits Roggenrolla. However, Roggenrolla stands still for a bit and evolves into a Boldore. Clay is impressed, but continues the battle, as Excadrill uses Horn Drill, though Boldore withstands the attack. Excadrill uses Drill Run, but gets stopped by Boldore. Suddenly, Boldore's crystals glow and releases Rock Blast, hitting Excadrill back. Boldore uses Rock Smash, and so does Excadrill, as these Pokémon clash.
However, Boldore manages to hit Excadrill, causing a major blast, which defeats Excadrill. Ash wins, pleasing the heroes. Later, Clay promises he will continue working at the mines and asks Ash never to forget this battle, giving Ash the Quake Badge. In the Pokémon Center, Iris admits at times she thought the match would be over, but Ash knows he can count on his Pokémon. Joy healed Ash's Pokémon and tells they could go to Mistralton Gym, which is close nearby. Pikachu is pleased and Ash reminds him they are always a team.
- The Japanese version of "Who's that Pokémon?" (Dare Da?) returns.
- The animation for when a Pokémon evolves is slightly modified in this episode. The glowing is dark blue and the lines surrounding the Pokémon are blue instead of a yellow-white color.
- Professor Oak's Live Caster: Golett
- Who's That Pokémon?: Excadrill (Japan), Krokorok (U.S.)
As Krokorok used Bite on Oshawott, the stripe down its back was coloured like the rest of its body instead of being the usual black.