The next drawing is Espeon, the Psychic Pokemon of the evolutions. You don't use stones like the original three to evolve it. You need friendship, a LOT of it. It also needs to be daytime when Eevee evolves so that it can be Espeon. If it's at night, it will be another Pokemon: Umbreon. Psychic Pokemon are always good to have on your team, or at least that's what I think.

Anyway, enjoy the art!