Gen 7 VGC Doubles
Linoone @ Mago Berry
Ability: Gluttony
EV's: 128 HP 64 Def 64 SpD 252 Speed
Nature: Jolly
-Simple Beam
-Extreme Speed
-Belly Drum/Roar
-Protect
Eevee @ Eevium-Z
Ability: Anticipation (scouts Fighting/OHKO)
EV's: 128 HP 64 Def 64 SpD 256 Speed
Nature: Timid
-Last Resort
-Baton Pass
-Stored Power
-Detect/Protect
This set is more for doubles with Eevee+Extreme Evoboost. Linoone is the fastest non-boosted setter (faster than Genesect, Xatu, Golduck, Grumpig, and Smeargle) for Simple Beam+Extreme Evoboost. If holding a Toxic/Flame Orb and Quick Feet ability, it's speed is boosted 50%! This strategy gives an insane +4 to all stats, that can be used with Stored Power (beware of Dark Pokemon), or Baton Passed to another. Protect/Detect for Fake Out.
Use Simple Beam on Eevee, then Z-move. Once set up, this is hard to shut down. Common stops are Taunt, Encore, Roar, Whirlwind, Circle Throw, Dragon Tail, Eject Button, etc. (Phazers). If you choose to use a Timid Xatu lead with Magic Bounce, that can at least help with the initial boosted Simple Beam Evoboost unless phazing is targeted at Eevee.
Linoone can also remove phazers itself with Roar. Common teammates receiving Extreme Evoboost are Tapu Fini/Lele, Moxie Gyarados, Mega-Gengar, Eviolite tank sweepers. Supporting Pokemon can be Magic Bounce Espeon with Psych Up to copy boosts, or any Pokemon with Psych Up!