Unfortunately no. Eevee is far too frail to work in any tier higher than LC as it is simply outclassed by every other normal type. Besides that, even with an eviolite, in any tier higher than LC, its bulk would be as good as nothing. Even opposing LC Pokemon can make quick work of an Eevee holding an Eviolite.
Even in LC, the only thing that makes Eevee an honourable mention is its spooky ability Adaptability that enables it to bop every second Pokemon with Return / Double Edge.
The fact that there is an eeveelution available in every tier doesn't help Eevee either as it would simply be outclassed by its Eeveelution.
I'm very sorry to disappoint you but Eevee has never been viable in any tier higher than LC and will most likely never be viable in any tier higher than LC
However if you're still interested, this is its prime LC set:
Eevee @ Choice Band / Life orb
EVs: 236 Atk / 36 Def / 236 Spe
- Quick Attack
- Iron Tail