Quoted By:
252+ Atk Life Orb Landorus-T Earthquake vs. 252 HP / 252+ Def Eevee: 274-324 (87.2 - 103.1%) -- 18.8% chance to OHKO
252+ SpA Rotom-W Hydro Pump vs. 252 HP / 0 SpD Eevee: 241-285 (76.7 - 90.7%) -- guaranteed 2HKO
252+ SpA Heatran Fire Blast vs. 252 HP / 0 SpD Eevee: 280-331 (89.1 - 105.4%) -- 31.3% chance to OHKO
252 SpA Life Orb Latios Draco Meteor vs. 252 HP / 0 SpD Eevee: 394-464 (125.4 - 147.7%) -- guaranteed OHKO
252+ Atk Life Orb Excadrill Earthquake vs. 252 HP / 252+ Def Eevee: 261-308 (83.1 - 98%) -- guaranteed 2HKO
252 Atk Garchomp Earthquake vs. 252 HP / 252+ Def Eevee: 178-210 (56.6 - 66.8%) -- guaranteed 2HKO
252 Atk Choice Band Talonflame Brave Bird vs. 252 HP / 252+ Def Eevee: 231-273 (73.5 - 86.9%) -- guaranteed 2HKO
252 SpA Life Orb Gengar Sludge Bomb vs. 252 HP / 0 SpD Eevee: 273-321 (86.9 - 102.2%) -- 12.5% chance to OHKO
So of the top ten currently most used in OU, four can't OHKO without a crit, three are dependent on high damage rolls and three do OHKO.
It's reasonably to assume that at some point in the game, you'd be able to bring Eevee in to get a single boost off.
