Espeon was out-classed by almost every other Psychic type because of its poor move-pool. Magic Bounce made it special.In 3rd place comes Espeon and it's Magic Bounce.....Actually no Venusaur comes in 3rd not Espy.Toxic Heal,Multiscale and Magic Guard just made 3 already good pokemons alot better without making them broken.Hydration changed Vaporeon as much as Insomnia helped Delibird...it's nice but it's that nice.....
Also, Hydration is a ton better than Insomnia. Insomnia was just redundant; Hydration gave Vaporeon a reliable healing in the rain, which is everywhere now. Not only that, but it can't be paralyzed or toxic-stalled or whatever. It's really good, and it sets Vaporeon apart from Jellicent.