My nomination for Aurorus is
Vileplume!
Vileplume @ Assault Vest
Ability: Effect Spore
EVs: 248 HP / 252 SpA / 8 SpD
Modest Nature
- Giga Drain
- Sludge Bomb
- Hidden Power [Fire]
- Moonblast / Infestation
Explanation
So I chose this weird Vileplume set because I think it compliments Choice Specs Aurorus quite well. Vileplume resists many of Aurorus's weaknesses such as Fighting and Water, while having the options and also bulk to deal with Fighting, Grass, Steel, Ground and Rock types. Aurorus on the other hand, deals with the some of the Fire, Ice and Flying types that Vileplume is weak to.
Having an Assault Vest on Vileplume allows it to take many super-effective moves really well while being able to heavily damage the opposing threat. The extra bulk on HP and SpD investments coupled with Assault Vest allow Vileplume to live the "super-effective coverage moves (non stab)" really well (such as Ice Punch from Sawk and Fire Blast from Weezing). Vileplume is also a good switch in to priority moves that damage Aurorus badly such as Bullet Punch, Aqua Jet and Mach Punch. Giga Drain is Vileplume's main way to deal with Aurorus's Water type weakness and also it is main source of recovery. Sludge Bomb is another stab move that deals with the Grass types that naturally out speed Aurorus such as Ludicolo, Lilligant and Shiftry. Hidden Power [Fire] deals with the Steel Types and provide coverage for annoying Bug types such as Vivillon and Scyther. Lastly, Infestation is meant to trap in vulnerable targets who are unaware of the viability of this set and watch them struggle to switch out, while Moonblast provides coverage against Fighting types.
What this core lacks
Psychic Type Coverage- Aurorus isn't very reliable on taking out Psychic type threats that Vileplume is weak to. Also, fast Psychic types such as Jynx can easily take out Aurorus with their coverage moves.
Rapid Spin/Defog Support- Since Aurorus will be switching out a lot, having hazards on the field will make it a lot harder for Aurorus to switch in and out. However, Vileplume will be able to get rid of Toxic Spikes as long as it is alive.
"Hard Hitters" Coverage- Pokemon such as Tauros and Kangaskhan can severely chunk Vileplume with Double Edge due to the lack of Def investments.
Archeops- The only thing it has to be afraid of is Stone Edge or Rock Slide missing Aurorus. Also Vileplume is unable to take an Acrobatics well. However, it is very easy to take Archeops out if it gets crippled or in Defeatist range.