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Mikey being inducted into the Knights
The Knights of the E Stone (Japanese: Ｅストーン騎士団 Order of the E Stone) is an evolution-worshiping cult active in Stone Town. It appears exclusively in The Electric Tale of Pikachu.
The Knights of the E Stone believe that unevolved Pokémon are worthless and evolved forms are superior. According to the Eevee brothers, joining the Knights is a family tradition for them.
The Knights appear in To Evolve or Not to Evolve, That Is the Question! when Ash Ketchum, Misty, and Brock follow Mikey to their building. Ash and his friends witness Mikey, an inductee to the Knights, being yelled at for not evolving his Eevee because he likes it the way it already is. Ash goes to defend Mikey, but this only brings the wrath of the Knights upon himself in the process.
The Knights decide to give Ash and Mikey a challenge: if they can beat their representatives, the Eevee brothers, in battle, then Mikey will be able to join without the need to evolve his Eevee. The next day, Ash and Mikey go to challenge the Knights; Ash easily defeats Rainer and Pyro with his Pikachu. The last battle pits Mikey and his Eevee against Sparky and his Jolteon. Mikey has some trouble at first due to the lack of moves Eevee has, but Ash uses a TM on Eevee that allows it to learn the move Mimic. With Mimic, Eevee is able to defeat Jolteon, thus making Ash and Mikey the winners.
Mikey is then inducted into the Knights, while Ash refuses an offer to join given by the Knights' leader.