Pokemon GO's ever-evolving wonder, Eevee, is prone to change due to its unstable and constantly shifting molecular structure.
With the upcoming inclusion of its Sylveon evolution, Eevee will have a total of eight different evolvable forms. Three in particular are mostly up to chance (Jolteon, Flareon, Vaporeon), while the other five evolutions require different mechanics in order to trigger the change in the player's Eevee.
Pokemon GO currently has a nickname-based trick in order to get their desired evolution, but this only works once.
For subsequent evolutions, trainers will need to put in a little extra effort.
For Pokemon GO players evolving Eevee's forms for the first time, the road is significantly easier than those who have already evolved Eevee before. In the event players haven't evolved a specific Eeveelution before, the tried-and-true nickname trick will suffice to begin evolution.
The process for this is simple. All that is needed is to change the player's Eevee's nickname to one of the following nicknames before using candy to start the evolution. The Eeveelution of choice is guaranteed the first time its nickname is used during evolution, but the trick will not work afterwards.
The Eeveelution nicknames currently known leading up to Sylveon's release are:
Although the nickname trick is helpful when first acquiring the Eeveelution, most Pokemon GO players have already evolved certain forms at least once, making the nickname trick ineffective. For these players, they'll need to rely on the traditional mechanics for evolving Eevee, and the majority of its forms require special attention and assistance. The methods are: