Here's how you evolve Eevee:
Vaporeon - Water Stone
Jolteon - Thunderstone
Flareon - Fire Stone
Espeon - Sun Ribbon + 1-star IQ at least
Umbreon - Lunar Ribbon + 1-star IQ at least
Leafeon - Mossy Rock
Glaceon - Frozen Rock
First thing you should do is always check the missions on the Job and Outlaw boards, every time they refresh. Just about any item in the game, including evolution ones, can be included as a reward. They'd be very rare, but it's possible. It's how I got a Sun Ribbon. Otherwise, you need to get lucky and find the items out in the dungeons, generally via Kecleon Shops.
For Water/Thunder/Fire Stones, you need to find a Common Evolution Shop. These appear in Mystifying Forest, Lake Afar, and Midnight Forest with a 9% chance and on odd floors only. If you find one, there's a variety of evolution items that will appear in it with an 11.11% chance of each item. They will cost a decent amount of money, though, so make sure you bring a lot.
For the Mossy/Frozen rocks, you need a Special Evolution Shop. These appear in Happy Outlook (8% chance, odd floors), Mt. Mistral (9% chance, odd floors), Shimmer Hill (9% chance, even floors), and Lost Wilderness (8% chance, odd floors). They have a large variety of rarer evolution items, with a 5.55-5.56% chance of any of them appearing. Again, they will be fairly pricy.
And lastly the Sun Ribbon and the Lunar Ribbon (which are required for a lot of happiness-evolution Pokemon) cannot be found in Kecleon Shops. You need to use the Job/Outlaw boards for these. Sun Ribbons can only be found in Golden Chambers, so look for missions that send you to one of those, and bring along a Mobile Scarf. Lunar Ribbons can only be found as a job reward, and only on jobs that have a 5* to 9* difficulty. Also keep in mind that your Eevee will need at least a 1-star IQ to evolve, so get it a lot of White or Orange Gummis at Marine Resort and take a trip to the cafe.
Does all of this sound like too much? Well you can actually recruit Eevee evolutions in the wild in some dungeons, but they're pretty hard to nab, given their negative recruit rates (-12% and -10%). You have the best chance if your leader is at least Level 90 and is holding the Amber Tear or Golden Mask. If you'd like to try your hand at recruiting, here's the dungeons where they can be recruited (they can be found in other dungeons, but they don't allow recruiting):
Vaporeon - Lake Afar (Floors 13-24)
Jolteon - Spacial Rift + Deep (Floors 1-9, 11-15, D1-4, D6-9)
Flareon - Dark Crater + Deep (Floors 1-15, D1-14), Giant Volcano (Floors 1-19)
Espeon - Marine Resort (Floors 1-19), Shimmer Hill (Floors 1-17)
Umbreon - Concealed Ruins (Floors 1-29), World Abyss (Floors 1-29)
Leafeon - Sky Stairway (Floors 1-49)
Glaceon - Crevice Cave (Floors 1-10), Lower Crevice Cave (Floors 1-4)
You can also recruit more Eevees in Mystifying Forest (Floors 1-13) and Mystery Jungle (Floors 1-29). They're much easier to recruit, with a rate of 8.2%.
I hope all of this helps you!
(Expert) - 10 years ago