Even though I dont play NU, I have somewhat of an idea on what i'm doing (inb4 JCM sees this)
Ludicolo @ Life Orb
Trait: Swift Swim
EVs: 252 SAtk / 252 Spd / 4 SDef
Modest Nature
29 HP IVs
-Rain Dance
-Hydro Pump / Surf
-Giga Drain
-Ice beam
Set is simple. Allows you to set up Rain, becom faster than everyone else, and sweep. Hydro Pump is if you want more power, and Surf is if you want reliability. Giga Drain allows you to have a reliable mean of recovery, while still hitting Alomamola and Golurk and Seismitoeds who have swift swim as well. Ice Beam lets you pick off grass types and flying types. 29 HP Evs for minimal LO damage.
Next, we have the mighty Cacnea! Jk, it's Cacturne, and it's one hell of a Pokemon.
Cacturne @ Life Orb / Leftovers
Trait: Water Absorb
EVs: 252 Atk / 252 Spd / 4 HP
Adamant Nature
-Swords Dance
-Seed Bomb
-Sucker Punch
-Spikes / Substitute / Drain Punch
Simple set. You can use this guy as a Spiker or as a physical force to be reckoned with. Start off by boosting that high base 115 Atk stat, and it's pretty much game. Sucker punch is priority, and after +2, not much can take it with ease. Seed bomb screws over Alomamola, who can Scald burn you, thanks to water absorb. Finally, the last slot is open to you. Spikes to help out teammates, Sub if you dont wanna die due to toxic, or would like to make Sucker punch predictions easier. Finally, Drain Punch so you can have a way to hit Skuntank, and have reliable recovery.