A Ghost-Type Eevee

Ghost-type Pokemon have been around since the first generation and have been fan favorites. A ghost type Eevee would only bring more love to this special type of Pokemon. A player would get the ghost type Eevee in a very similar fashion to the Pokemon Shedinja. A player would have to have Eevee and an open slot in their party, along with an extra Pokeball in their bag, and have Eevee faint during the fight. Once Eevee fainted the free spot in the party would be filled by the ghost type eeveelution as it rests peacefully. This is similar to how the Pokemon Shedinja is found in the games, because when you have the Pokemon Nincada in your party along with an extra free slot and an extra Pokeball in your bag you have a chance of a Shedinja appearing in your party.

A Steel Type Eevee

Steel types were introduced in generation two and they are very cool and strong being beloved by players but underrated in terms of franchise merchandise sales so having a steel type Eevee could boost steel-type love by fans. I have given a lot of thought to how a steel-type Eevee would be evolved and I personally think the easiest way would be to take something that is already in the game as a mechanic that players are already used to using. A metal coat item that is found in mines and after you beat the elite four can be bought in stores. If your Eevee's strongest stat is defense and you use a metal coat on it then you will get a steel-type Eevee.

A Rock Type Eevee

A rock type Eevee is something that most fans have been on the fence about since rock types are usually fossil type Pokemon which are a fun challenge to find in the games but seem rather difficult to get more than one of in the games. Fossil Pokemon are great and have been around since the first generation so I think having an ancient type of Eevee that has been lost to time would be pretty cool and a fun new way to revive the fossil Pokemon love. The way you would get the rock type is by finding the Eevee fossil and taking it to the science lab and reviving it, the same way that a player would get any other fossil Pokemon like Anorith, Lileep, and Aerodactyl.

A Flying type Eevee

Flying-type Pokemon are usually birds of some kind or they have wings so making the small dog-like Pokemon of Eevee fly might be difficult and that also makes it a bit harder to get a flying type Eevee. There is a way to teach Eevee the move bounce, which is a flying type move that lets non-flying type Pokemon leap in the air on the first turn and then land, damaging the opponent, on the second turns. This move which is traditionally learned by non-flyers could be taught to Eevee through a character in the game called the move reminder. The Pokemon move reminder is a valuable character that has helped players since the fourth generation, he has the ability to reteach a Pokemon a move from when it was an earlier level in the game. Using this character, once an Eevee reaches a certain level it can be brought to the move reminder, learn the move bounce and evolve into the flying type the next time it goes up a level.

A Dragon Type Eevee

Dragon-type Pokemon are very strong and very intimidating making them great for players to use in battle on a regular basis but not exactly the most ideal for the cute and cuddly nature that has people in love with Eevee and the eeveelutions. However, having a cuter dragon type would make many fans happy. There are only 50 dragon type Pokemon in the games through all seven generations making them rare and hard to get so this eeveelution should be no different. Players would use the long process of breeding a female Eevee with a male pure dragon type Pokemon like Dratini, Bagon, Goomy, or Axew. This will be very difficult and tedious for players because the pokemon have to be compatible for breeding and the chance of breeding the rare dragon type eeveelution will be much lower than getting another Eevee or regular dragon type being used.

A Poison Type Eevee

Pure Poison-type Pokemon are interesting given that there are so few of them in the games, only 16 in total as of generation seven. These type of Pokemon are often over looked as not as useful to players or not being cute enough. I doubt that an eeveelution would do much to help the number of pure poison-types but it might bring fans a new light to the usefulness of poison types and how effective they could be against some other Pokemon types. The way to get this eeveelution would be very different than others but still interesting for players. Your Eevee must be hit by a poison-type move, become poisoned, then level up while being poisoned to become the poison-type Eevee.

A Fighting Type Eevee

A fighting-type Eevee would be extremely tough and could even be a great asset to players because most fighting type Pokemon are difficult to get but when used are great for battling. Many players overlook them because most of the Fighting-types that are mixed with other types are unable to evolve making them difficult to change stats or fun for players because it goes no further in the Pokedex. The way to evolve this eeveelution would be to go to the pokemon move reminder and learn a fighting-type move called Bulk up which raises the users attack and defense stats and once your Eevee has leveled up and raised its attack and defense stats enough it will evolve into the fighting type the next time it goes up a level.