WARNING: The following contains spoilers for Season 1, Part 2 Episode 1 of Pokémon Journeys: The Series "The Climb to Be the Very Best!" now streaming on Netflix.
Fans have patiently waited to see Ash Dynamax his Pokémon ever since the new anime began. The latest Pokémon battle transformation, introduced in Pokémon Sword and Shield, has made more than a few waves, especially for the alternate "Gigantamax" forms certain Pokémon can have. Ash and Goh encountered a Gigantamax Snorlax earlier in the series, but this episode marks the first time either of them has battled using a giant Pokémon. Of course, the Pokémon Ash chooses to Gigantamax is his trusty partner -- Pikachu.
Season 1 Part 1 ended with a cliffhanger, as a Gigantamax Drednaw poked its head into the stadium where the World Coronation Finals were taking place. Gigantamax Drednaw is as massive as it is strong -- even when tag-teaming with Goh, Pikachu's Thunderbolt and Scorbunny's Double Kick barely land a scratch. As the team runs from Drednaw's big chompers, Pikachu steps on a crack in the ground seeping Dynamax energy. Pikachu absorbs this energy and transforms into Gigantamax Pikachu. Ash orders Pikachu to Quick Attack in what might be the slowest Quick Attack of all time. Pikachu moves towards Drednaw, but is too slow and awkward in this form, tripping mid-attack into the stadium. Similarly with Iron Tail, in Gigantamax form Pikachu's Iron Tail is so heavy it has to hold its tail as it marches towards its opponent. Instead of physically attacking with the tail, Pikachu slams its tail into the ground, creating giant iron spikes that hit Drednaw.
Meanwhile, Leon heads outside to see what all the commotion is about and notices Ash fighting without a Dynamax Band. With this, Leon realizes that Ash is inexperienced with Dynamax battles and decides to help him out. The Champion tells him that in Pikachu's current form it can use G-max Volt Crash against the Drednaw. Ash orders Pikachu to use the move as Drednaw prepares its G-max rock attack. Pikachu jumps into the air and crashes down to gather enough energy for an insanely powerful thunder-like attack. With this, the Drednaw shrinks back to its normal size, as does Pikachu. Gigantamax and Dynamax only last for three turns, and since Pikachu used three attacks, it's time as fat Pikachu is up.
After the battle, Team Rocket head out to search for the shrunken Drednaw as Leon introduces himself to Ash and Goh. Later in the day, Leon overhears Ash's desire to battle him, and like the charitable, heroic champ he is, invites Ash to a battle inside the stadium. There, Leon and Goh give Ash the lowdown on Dynamax battles. Leon gives Ash a Dynamax Band so he can supersize his Pikachu inside the stadium and Goh informs Ash what all of Pikachu's Dynamax moves would be called. Now, the way Dynamaxing is usually done, a trainer returns their Pokémon to their Pokéball and uses the Dynamax Band's power to enlarge the Pokéball and send the newly Dynamaxed Pokémon back into the battlefield. Pikachu doesn't go into a Pokéball though -- he never has, really -- but Ash and Pikachu's bond is so great, they manage without that step.
After all this training is done, the battle begins. Ash sends out Pikachu, and Leon throws in Charizard. Ash has the type-advantage so seems Pikachu might have an easier time, but Leon isn't number one for no reason. Each attack Pikachu throws at Charizard, it Thunder Punches and knocks Pikachu back. Thunder Punch isn't even super-effective against Pikachu, nor is it getting any type-boosts from Charizard, so it really speaks to how strong Charizard is that it can use this move and cancel Pikachu's so easily. Ash finally goes for the Thunderbolt as Leon counters with a Flamethrower. It appears Pikachu is getting overpowered once again, but Ash Gigantamaxes Pikachu in the nick of time so it can take out Charizard's Flamethrower.
The tides turn in Ash's favor -- until Leon Gigantamaxes his Charizard. It dodges Pikachu's Max Strike and uses Max Airstream to land some damage. Pikachu uses Max Steelspike followed up by G-max Volt Crash. With a move as powerful as Volt Crash it's likely Pikachu could one-hit KO Charizard, but Charizard counters with its own Gigantamax move, G-max Wildfire. This KOs Pikachu and the match is over.
Leon and Ash share some friendly banter after the battle, as they both promise to battle again in a real tournament fight. Ash now has a new goal for becoming a Pokémon Master, climb up the rankings of the World Coronation Championships and defeat Leon.