So I have been reading through this and was wondering something. How viable would Trick Room be? Only Espeon has access to it, and while it would all but cripple Espeon itself, would it not also give Flareon, Glaceon, and even Vaporeon, a shot at being a powerful sweeper?
The arguments for Flareon are all over this thread so I will not go into them here, just imagine all the good stuff from that power now with tied for the second fastest (behind only Eevee, who could also benefit from TR) in the meta.
While Glaceon's move pool is rather limiting, access to signal beam and your choice of STAB, hits most of the meta for at least natural damage, and if you really wanted to you could add water pulse for Flareon coverage.
Vaporeon has the higest HP of anyone allowed, and with a special attack stat beat only by Espeon and Glaceon, you have the potential for a bulky tank after the speed boost from Trick Room.
While it may not be the best strategy, it certainly could prove to be an effective counter to Chlorophyll Leafeon, and anyone wearing a scarf. Plus the surprise factor may just be enough to help out.
Just a thought.