http://bulbanews.bulbagarden.net/wiki/Online_Eeveelution_game_to_interact_with_Dream_World
The obvious choices are Umbreon and Flareon.
Here's my idea:
Grab guts Flareon, train him until he gets fire fang and facade. Give him the toxic orb. It's like flame orb Swellow/Heracross, only so stupid no one will see it coming. Though, Flareon's attack is MUCH higher than Swellow's, and slightly higher than Heracross's, so this may work.
Fully-evolved Pokemon with guts:
Raticate: 81
Machamp: 130
Flareon: 130
Heracross: 125
Ursaring: 130
Swellow: 85
Hariyama: 120
Luxray: 120
Conkeldurr: 140
Throh: 120
Conkeldurr, wow.
Conkeldurr + guts + facade + flame orb = rape
Conkeldurr + sheer force + rock slide + life orb = rape (charizard edition)
GUYS WHY DIDN'T WE THINK OF THIS SOONER
(guts/facade/flame orb team)