Prior to Battling with Elegance and a Big Smile!, Sawyer received Sceptile as a Treecko from Professor Birch. It battled with a wild Taillow sometime afterwards. It was unable to deal with Taillow the first time. Using the notes that Sawyer wrote down, Treecko practiced its movements and was able to battle Taillow properly the second time.
Treecko made its first onscreen appearance in Battling with Elegance and a Big Smile! where it had a battle with Clemont's Luxray at the Lumiose Gym. It attempted to use Razor Leaf* earlier on. However, this left an opening for Clemont to attack. Afterwards, since the timing of Treecko's attacks were off, Treecko was defeated by Luxray's Wild Charge, costing Sawyer the match.
Treecko reappeared in A Fashionable Battle! where it partook in a Double Battle with Bagon against Ash's Frogadier and Hawlucha. Although Treecko worked with Bagon to battle Hawlucha, the combination was interrupted by Frogadier's Water Pulse. Treecko used Bullet Seed twice on Frogadier but Frogadier dodged both of them. Treecko was then defeated by Frogadier's Cut despite having the type-advantage. Even though Bagon was left standing, Ash and Sawyer's Double Battle was interrupted when a fashion show was about to start.
Sawyer sent Treecko out in Fairy-Type Trickery! to watch Ash's Gym battle with Valerie. As spectators, he wanted Treecko to watch the battle so that both of them would learn a lot.
In Rivals: Today and Tomorrow!, Treecko helped Sawyer look for his notebook after it slipped out of his front pocket. After Slurpuff found it from Team Rocket as they thought that it belonged to Steven Stone instead, Treecko battled Team Rocket alongside with Pikachu. All of the attacks performed by the Pokémon, including Treecko, canceled each other out but Pikachu's second Thunderbolt sent Team Rocket blasting off.
During Sawyer and Ash's three-on-three battle, Sawyer sent out Treecko as his last Pokémon against Ash's Frogadier. Both Pokémon performed moves that were super effective against each other, as well as outspeed each other. Although determined to defeat Frogadier, Treecko evolved into Grovyle and learned Leaf Blade in the process. Despite the evolution, Grovyle still had trouble keeping up with Frogadier's movements. Grovyle went for Leaf Blade while Frogadier went for Cut. Both moves were elegantly dodged and then went for Bullet Seed and Water Pulse, respectively, causing smoke. Grovyle cleared the smoke with Leaf Blade, but Frogadier disappeared before it could happen. Frogadier launched another Water Pulse, which successfully connected with Grovyle, defeating it. As a result of the loss, the beginning of a rivalry between Grovyle and Frogadier began to develop.
Grovyle reappeared in From A to Z! where it chased after a group of Dodrio so that Sawyer could catch one.
Grovyle fought alongside Ash and his Pokémon against Celosia and three Team Flare Grunts. It was able to free Squishy from Celosia's Drapion's grasp with Leaf Storm. Grovyle fled alongside Ash and company when Pikachu's Thunderbolt and Drapion's Sludge Bomb clashed with each other, causing smoke.
Later, Grovyle fought Celosia and the three Team Flare Grunts again. It was assisted by Frogadier despite their rivalry. They continued their battle when Serena, Clemont, and Bonnie attempted to take Squishy to safety. Their battle was stopped when Celosia and the three grunts fled. After dealing with Team Flare, Sawyer and Grovyle left Ash and his friends the next day.
It reappeared in A Meeting of Two Journeys! where it was revealed to have evolved into Sceptile. It was used in a battle against Ash's Greninja. Although Sceptile was able to match Greninja and even gained the edge due to its type advantage, it ultimately lost by a single hit when Greninja transformed into Ash-Greninja.
Lightning Rod activated as a Mega Sceptile
In A Full-Strength Battle Surprise!, it was used to battle Greninja once again. Although they were even at first, Sceptile gained the upper hand and eventually won as Ash and Greninja repeatedly attempted and failed to access their Ash-Greninja form, allowing Sceptile to hit Greninja with Leaf Storm before settling the battle with a decisive Leaf Blade.
In Valuable Experience for All!, Sceptile is sent out as Sawyer's final Pokémon to battle against Tierno's Blastoise in the quarterfinals of the Lumiose Conference, and was revealed to have been equipped with a Sceptilite, which Sawyer referred to as his "secret weapon". Blastoise started with an Ice Beam, which Sceptile intercepted with a Leaf Storm. Blastoise then tried to execute a Hydro Cannon, but Sceptile dodged it and landed a Leaf Blade in return. Blastoise charged towards Sceptile with Skull Bash, but Sawyer commanded Sceptile to intercept it with Frenzy Plant, tossing Blastoise into the sky. As it falls, Blastoise managed to summon thunderclouds with Rain Dance, and upon impacting the ground, it is knocked out.
Tierno then summoned his last Pokémon, Raichu, and ordered a Thunder, ensuring that, with the support of Rain Dance, the Electric-type move would not miss. Before Raichu could release her Thunder, however, Sawyer used his Key Stone to Mega Evolve Sceptile. Raichu completed his attack, and Sceptile comes through it completely unscathed. Sawyer revealed that, as a result of Mega Evolving, Sceptile's Ability is now Lightning Rod, rendering Thunder useless. Sceptile charged towards Raichu with a Dragon Claw, and Raichu tried to counter with Focus Blast, but Sceptile slashed through the attack and landed the blow on Raichu, knocking him unconscious and winning the battle for Sawyer, making him the fourth and final semifinalist.
Its rivalry with Ash's Greninja
In A Riveting Rivalry!, Sceptile was the final Pokémon chosen by Sawyer during his Full Battle against Ash in the semi-finals of the Lumiose Conference. Sceptile initially went up against Pikachu (who had already taken damage during a hard battle against Sawyer's Aegislash) and quickly knocked him out. Sceptile then went up against its rival Greninja again, who had now mastered the Ash-Greninja form. Greninja started the battle with a Water Shuriken, which Sceptile destroyed with its Dragon Claw. Greninja then summoned clones with its Double Team, which Sceptile wiped out by using Frenzy Plant. Greninja emerged unscathed from the attack, and used Cut to clash with Sceptile's Leaf Blade.
Both Pokémon then transformed to their respective more powerful forms, Ash-Greninja and Mega Sceptile. Sceptile attacked with another Frenzy Plant, which Greninja slashed through using Cut, and then launched off its Water Shuriken, which was countered again with Dragon Claw. Both Pokémon then kept exchanging and clashing with their powerful and fierce attacks, with Sceptile getting struck by powerful hits from Aerial Ace, before retaliating with Leaf Storm. After clashing using Cut and Leaf Blade again, Greninja was thrown into the air by Leaf Storm. As Sceptile was about to finish it off with Frenzy Plant, Greninja was able to regain its footing and run on top of the roots. Sceptile tried to corner Greninja with Frenzy Plant, but while using its shared senses with Ash and its full trust in him, Greninja was able to dodge every single Frenzy Plant and slice through them using Cut. As its back-mounted shuriken grew to massive size, Greninja fired off the Water Shuriken while Sceptile countered with Leaf Storm, causing a large explosion. After the smoke cleared, only Greninja remained standing, giving Ash the win and eliminating Sawyer from the tournament.
Sceptile appeared again in Kalos League Passion with a Certain Flare!, where it helped console Sawyer, who was feeling upset as a result of their loss to Ash and Greninja.
In A Towering Takeover!, Sawyer used Sceptile's Leaf Blade to help defend people against the giant roots attacking Lumiose City, soon joined by Shauna's Ivysaur, Tierno's Blastoise, and Trevor's Charizard. It was later seen at the Pokémon Center, helping the citizens of Lumiose City. It was also seen watching the battle against the Giant Rock unfold on television in Rocking Kalos Defenses! and Forming a More Perfect Union!.
Sceptile appeared in a flashback in Facing the Needs of the Many!.
Sceptile appeared again in Till We Compete Again!, where it was standing beside Sawyer as he and Steven were investigating the Megalith that was recently at the Lysandre Labs.