The Eighth Wonder of the Sinnoh World! (Japanese: 電撃バトル！最後のバッジ！！ Electric Shock Battle! The Final Badge!!) is the 22nd episode of Pokémon: DP Sinnoh League Victors.
Ladies and Gentlemen, the time has arrived. Ash, finally, faces off against Volkner in a gym battle for the ages. Both of them have been waiting for this day. Will Ash be able to overcome a Gym Leader who's friends with a member of the Elite Four, and why is Dawn dressed like a cheerleader again?
Back at the Sunyshore Gym, Ash is going to have his battle with Volkner. Dawn, Buneary and Piplup, dressed as cheerleaders, support Ash like he did them. Flint explains to Brock many challengers come to the Gym to challenge Volkner, but as promised, Volkner waited for Ash to come before he can accept anyone else. Meanwhile, Team Rocket plan their "tower heist" once more to get the tower for the boss. Volkner sends Electivire and Ash his Torterra. Torterra starts with Leaf Storm, though is blocked by Fire Punch. Torterra attempts once more, but Electivire uses Fire Punch once more to stop the attack. Torterra uses Energy Ball and hits Electivire.
Torterra charges with Rock Climb, but Electivire stops him using Ice Punch, which makes Torterra defeated. Brock suspects the Ice Punch was a counter-measure against Ground-type Pokémon. Volkner is feeling "the spark", having his battle-spirit renewed. Ash calls Torterra back and sends Pikachu. Team Rocket attempt to enter the tower, but it is sealed. Pikachu uses Quick Attack, but Electivire dodges and retaliates using Fire Punch. Pikachu evades and uses Thunderbolt, but Electivire absorbs the electricity, as if nothing happened. Electivire attempts with Ice Punch and misses. Pikachu uses Thunderbolt once more, but with same result. Dawn wants to know why is this happening. Flint tells them it is an ability, which Brock realizes it is Motor Drive, which provides resistance against Electric attacks.
Pikachu uses Iron Tail, but with all the Electric attacks, Electivire evades in a second, as its speed is boosted. Electivire uses Fire Punch and hits Pikachu. Electivire uses Ice Punch and also hits Pikachu, but is affected. It attempts once more, but due to its last attack, Pikachu's Static ability activated, causing Electivire to be paralyzed. Pikachu uses Iron Tail and Electivire goes to counter with Ice Punch, but is paralyzed and takes damage. Electivire goes to use Ice Punch, but gets defeated by Iron Tail. Volkner calls it back and sees how fun and exciting it can get. Brock calls this a tie, but Flint lets him know Volkner has an ace; a power that he has not yet shown. Team Rocket attempt to enter the tower through the back door, but get electrocuted when touching the door itself.
Volkner sends Jolteon and Ash his Infernape. Infernape punches it using Mach Punch, while Jolteon retaliates using Thunderbolt. Jolteon follows using Shadow Ball, but misses. Jolteon continues to use Shadow Ball, but Infernape punches the balls. Jolteon jumps to use Shadow Ball, but Infernape defeats it using Mach Punch. While they are battling, Team Rocket gets into the tower and goes towards the upper stages. Volkner sends Luxray; Ash calls Infernape back and sends Pikachu. Pikachu starts using Quick Attack, but gets canceled by a Shock Wave. Pikachu retaliates using Iron Tail and continues to do so, though Luxray uses ThunderFang and stops Pikachu. With another Shock Wave, Pikachu is defeated. Team Rocket goes to a room, but see it is not the operating room. When they try to get out, the door got stuck.
Volkner admits it is sad to see this is the last battle, so he and Ash promise to give on the next their very best. Ash sends his Infernape back and uses Flamethrower, but Luxray counters with Shock Wave. Infernape uses Mach Punch, though it hits an illusion caused by Double Team. Luxray bites Infernape using ThunderFang. Luxray uses Shock Wave, but Infernape dodges. Infernape goes to use Mach Punch and gets bitten by ThunderFang. Luxray goes to bite once more, but Infernape digs, so Luxray gets it out using Iron Tail on the ground. Volkner does not wish to end this, but orders Luxray to use ThunderFang to defeat Infernape. Ash tries to get Infernape up by encouraging it. Team Rocket attempts to get out by pressing buttons, but this causes the machines to flinch and spark, as they blast off.
This causes the lights to go off. Volkner asks Ash if he wants to continue and Ash agrees. As Luxray goes to use ThunderFang, Infernape stands up and lights the room, as the rage inside its body is piled up; Blaze is activated. Flint knows Volkner and Ash have not much time or chances to win, making it more exciting, but Brock and Dawn worry Infernape can outrage and hit everything and everyone. Infernape uses Flamethrower and although it misses Luxray, it continues to melt everything. Ash tells it to stop and goes to him. Ash reasons with it, as they have a battle to finish, which Infernape accepts. Infernape uses Flamethrower, which Luxray narrowly dodges. Luxray uses ThunderFang and bites Infernape, but Infernape gets it off using Mach Punch. Luxray uses Iron Tail, however, it gets defeated by Flame Wheel.
Ash wins the battle and hugs Infernape. With the lights on, Volkner presents Ash the Beacon Badge, his final badge. Later, Volkner thanks Ash for this battle. Flint lets them know in the Lily of the Valley is where the Sinnoh League will be held, in a month, which they need to take a boat, like one at the Sunyshore ferry.
- Volkner used three of the four Pokémon from his Platinum Team, while the other Gym Leaders used their Diamond and Pearl teams.
- This is Ash's first Gym Battle since Sliding Into Seventh!, 52 episodes and just over one year previous, marking the longest gap between Gym Battles in the same region.
- This is the first time Ash's Pikachu defeated a member of the Electabuzz evolutionary line.
- The dub title comes from "Seven Wonders of the World", which refers to historic landmark buildings.