Ludicolo @ Leftovers
Ability: Swift Swim
EVs: 252 Def / 212 SpA / 44 Spe
Modest Nature
IVs: 0 Atk
- Rain Dance
- Hydro Pump
- Giga Drain
- Ice Beam

Regirock @ Leftovers
Ability: Clear Body
EVs: 224 HP / 252 Atk / 32 SpD
Adamant Nature
- Hidden Power [Rock]
- Curse
- Counter
- Earthquake

Gyarados @ Leftovers
Ability: Intimidate
Shiny: Yes
EVs: 160 HP / 252 Atk / 96 Spe
Adamant Nature
- Taunt
- Dragon Dance
- Hidden Power [Flying]
- Earthquake

Very fun team that gets a lot of nice matchups, double- or even triple-beating many big threats. Zapdos is unfortunately threatening to this team, but Regirock almost always wins by clicking curse turn 1. 
Ludicolo beats most opposing Waters and Rocks. Giga Drain helps the Starmie matchup (though HP Grass can be run if you prefer the power) while Ice Beam beats Sceptile and some Salamence. Speed to outrun Sceptile and Zam in rain.  
Regirock is the Electric answer, as well as the answer to numerous physical attackers. HP is for Choice Band Metagross, while attack is max and the remaining EVs are put in spdef to beat Zapdos as reliably as possible.
Gyarados rounds out the team by handling Fighting-types and Registeel (vs Registeel: taunt t1, dragon dance t2, then play accordingly depending whether or not your opponent reveals Counter), as well as some miscellaneous mons the other two don't beat. Speed to outrun Adamant ttar (Gyara is the worst pick into ttar, but still has decent odds to win), max attack, HP dump.