I'll go on a bit of a different path, but I really like this moveset.
Ability: Sand Veil
EV's: 252 Atk/ 128 Def/ 128 Sp, Def
Nature: Adamant (Atk Up, Sp. Atk Down)
Earthquake (STAB, Power)
Fire Fang (Covers Ice and Grass weaknesses, plus Bug resistance)
Thunder Fang (Covers water weakness)
Sandstorm (I'll explain)
Donphan holds the Smooth Rock, making Sandstorm last for eight turns. It deals damage to most opponents, but not you. Plus, it raises his evasion by 25%. It can dodge, while we keep attacking with the help of a sandstorm. Nice and easy! Tell me what you think please!