Holy shit, this thing is powerful. I just got 6-0'd off this fuck and decided to try him out for myself. I was not disappointed. Give this a shot:

Gyarados @ Gyaradosite
Ability: Intimidate
Shiny: Yes
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature
- Waterfall
- Earthquake
- Ice Fang
- Dragon Dance

Waterfall is obvious. Mold breaker earthquake is game-breaking. It destroys threats that resist waterfall and is capable of hitting hydreigon and rotom-w off their levitating perch. Ice fang is there for dragonite and salamence.

There is nothing that can stop this behometh once it gets a DD under its belt. Forget M-Kanghaskhan, M-Gengar, and M-Blaziken and say hello to the beast of the seas.