Eevee is garbage, don't use it. It's less powerful than Flareon, has awful stats, and an even worse movepool than the others. The sole reason to use it would be for the fact that CB Quick Attack 2HKOs the 65/60 defense crowd (Jolteon, Espeon, Flareon), but rotating doesn't take up a turn and you are just inviting Leafeon and Umbreon to set up on you. If you want a powerful physical attacker, Adamant Guts Flareon at least 2HKOs the entire metagame with the exception of 252/252 Bold Vaporeon which must have Leftovers to escape the 2HKO from Facade. CB is most certainly not banned in Eevee Cup.