Mr Mime @ Leftovers
Ability: Soundproof
EVs: 252 HP / 104 SpA / 148 SpD
Calm Nature (+SpD, -Atk)
- Psychic
- Hidden Power Rock
- Psych Up
- Magic Coat / Light Screen
Why yes, this set would be retarded in any meta other than RU. But one of the few things Mr Mime can boast is being an excellent Yanmega / Venomoth lure. With the above EVs, Mr Mime is not 2HKO'd even by Yanmega's Choice Specs Air Slash thanks to Leftovers recovery, and with Soundproof it's immune to Bug Buzz. Hidden Power Rock is a clean OHKO on uninvested Yanmega and a clean 2HKO on Subroost Moltres. Light Screen lets you provide team support; since you can tank Yanmega's attacks for much longer under Light Screen, you can use Psych Up to gain its speed boosts, which is nice.
This set is also useful against Venomoth, although you might need Magic Coat to help deal with Sleep Powder. If you can steal its boosts using Psych Up, Mr Mime could attempt a mini-sweep, effectively being immune to most special attacks. Psychic will 2HKO offensive Venomoth attempting to get Quiver Dance boosts, and will OHKO those who don't.
I'm not sure about how viable this set is, but given how much Yanmega and Venomoth are used, I can certainly see some merit.