>>21773226None.
Seriously none.
Their main problem is their type and their stats distribution.
You can only make them slightly better then they currently are, but still letting them remain in their respective tiers.
Flareon: Crunch, Cotton Guard, Night Slash.
Leafeon: Superpower, Night Slash (has Knock Off).
Glaceon: Flash Cannon, Freeze Dry.
Jolteon: Overheat, Dazzling Gleam.
Espeon, Vaporeon, Umbreon and Sylveon are already good in OU but since we are on topic those could perfectly gain more toys to play with.
Umbreon: Calm Mind, Moonblast, Amnesia.
Espeon: Solar Beam, Aura Sphere, Amesia.
Vaporeon: Amnesia.
Sylveon: Aura Sphere.
Eevee: Foul Play, Reflect Type, Assist.
Upon evolution Foul Play and Reflect Type can actually play a significative role for the stallish and defensive eeveelutions.
Note that I didn't try to give them all the possible broken coverage moves and other insane moves, I just think those moves could thematically and realistically fit them, even if some of those don't help them in the competitive scene.
