This Scyther a Bug/ -type Pokémon owned by Yas.
Biography
It is always fighting the Kaz's Electabuzz, and, like the Electabuzz, it becomes extremely violent when it sees the color red.
Scyther is first introduced in the episode Showdown at Dark City where it managed to easily dispatch the Kaz Gym Trainers. After the street fight, Scyther is seen again, sitting on the floor, with its blades crossed. when a female Yas Gym recruiter brings Ash, Misty, and Brock to the Gym to introduce them to the Yas Leader and explains how Ash and his "disciples" disposed of the three Kaz Trainers (Team Rocket trio), but the Yas Gym Leader wants to be the one who determines how strong they are and turns Scyther loose to attack Ash's Pikachu, but the latter uses the ketchup bottle as a shield, protecting it from its Cut Attack. As a result, Scyther gets its eyes covered in ketchup and saw everything around it in red. The now enraged Scyther then attacks its Trainer in an unrelenting fury, forcing the latter to return it to its PokeBall. After fleeing from the Gym, Ash and his friends latter find out that Scyther and Electabuzz both have a strong aversion to anything red and made all the necessary preparations to shift the tides against them.
Later, the Mantis Pokémon is sent out in another street fight. It used Swords Dance to power up its Cut move to fend off its opponents and destroys a building with Team Rocket on them. It then engages in battle with the Kaz's Electabuzz. Ash and his friends, with the help of the restaurant owner and three children, dump ketchup on their Trainers. Electabuzz and Scyther take notice and go totally insane to the point where their Trainers could no longer reason with them and starts attacking them in a crazed fury. Ash calls them out for using their Pokémon to terrorize the citizens of Dark City. He then decides that they had enough and had Bulbasaur dump ketchup on the two Pokémon. The two run into each other, knocking them out. Nurse Joy decides that neither of them will become an official Gym due to the way they treat their Pokémon and caused chaos in the city, but she does offer them an another chance at it.
At the end of the episode, both Scyther and Electabuzz helped both Gyms rebuild the city, to which it uses its swords to crave wood for them to use. They later chase Team Rocket (who are covered in ketchup) out of town, in their red-provoked wrath.