As an Eevee, Espeon was very energentic and outgoing. She also shows a playful demeanor that is typical for her species and is often seen on Ash's head, showing her affection by nuzzling him. Her playful and kind personality remained as she evolved into Espeon. Upon evolving, she has become more agile and skilled which led her to perform better battles by using her speed and psychic abilities to her advantage. Not only is she a adept battler, but an intelligent one as well.
History
Prior to Series
Espeon was mentioned to be caught as a Eevee at Celadon City by Ash. When Ash went to the room at the roof of the Celadon Mansion and found a Eevee in a Luxury Ball. When he opened the Luxury Ball, Eevee popped out and started to play with Pikachu. Ash later found out she was accidentally left behind by her trainer's family when her trainer, an elderly woman, passed away. When Ash decided it was time to leave, he decided to take Eevee with him, to which she happily agreed. She at some point evolved into Espeon.