Um, I didn't see a question like this, so I'd thought I'd ask, since Evo Pokemon are common in NU. Not counting stuff like Dusclops or Porygon2, since they're pretty OP'd with Evo and are in UU.
This includes LC Pokemon that are viable in NU, e.g. Ferroseed.
I'll post one as an example.
The Solosis evolution line is pretty awesome, not only sporting a cool design, but also a brilliant ability all the way through - Magic Guard - through all three of its stages. It's got some good coverage apart from STAB Psychic; Shadow Ball, Focus Blast, Energy Ball and Signal Beam, along with great support moves like Calm Mind, Recover and Trick Room. As one of the slowest Pokemon in the metagame, it can set up and fully utilise Trick Room by itself and sweep with a monster base sp. atk of 125, which is higher than Porygon2's base 105 sp. atk. Along with Magic Guard, Duosion has a lot to boast, since it can't be worn down by status or weakened by hazards. A lacking of good spinners in NU means that hazards are just things that NU players have to deal with.
Duosion @ Eviolite
Ability: Magic Guard
EV: 252 HP, 252 Def, 4 Sp. Atk
- Calm Mind
- Signal Beam
Psyshock and Signal Beam give almost full neutral coverage apart from Steel types. Psyshock for STAB, Signal Beam to cover dark types with an added chance of confusion.
Recover is self-explanatory; Calm Mind is there to further boost sp. def on top of Eviolite, but also boosting its Sp. Atk, leaving EV investment for HP & Defence.
Overcoat - while not taking damage from Sand or Hail would be nice, neither really exist in NU. Snover moved up to RU, and Hippopotas is not commonly seen in NU, even though it's a weather starter. Besides, even if Hail or Sand were in force, Magic Guard would protect Duosion anyway.
Regenerator (Hidden Ability) - while a very good ability in itself, Regenerator is not the optimum ability for Duosion, only because it has a better one.
Magic Guard - Duosion's brilliant ability. Immunity to hazards, weather, status draining and Life Orb recoil (should you choose a Life Orb set), this allows it to be a much more significant threat, along with its decent bulk.