>>36670659It's in a modestly decent (but not great) speed tier and would rather have some special bulk than anything else. Flower Gift would work out pretty well for it.
Generally, Eeveelutions get screwed hard since most of the shitmons of day's past get buffed but remain shitmons because it's either not enough or they just have bad qualities about them, while a well-placed stat buff or two along with a slightly widened movepool would mean a new world for some of them. 15+ defense would make Vaporeon a (slightly) better Bulky Water Type™. 15+ Attack for Umbreon with Bulk Up could let it take physical hits better and run Assurance (since it's going last anyway) or play Pursuit mind games while keeping its cleric role. Giving Ice real resistances and 15+ HP would make Glaceon's 110/95 defenses almost mean something and Freeze Dry would let it check Water types.
I love Flareon, but he will never be good. It is fated to die in one hit or be beaten within an inch of its life, use Flare Blitz, and die. Nothing short of completely rearranging everything sans Attack and getting a worthwhile Physical STAB that doesn't make it kill itself or some generic "make all normal type moves fire" ability will change that. I can dream that they will throw Flareon and the rest of the family a bone, but doubtful even with the shilling of the Switch game.