Dragonite @ Lum Berry  
Ability: Multiscale  
EVs: 192 HP / 64 Atk / 12 SpD / 240 Spe  
Adamant Nature  
- Dragon Claw  
- Roost  
- Earthquake  
- Dragon Dance

Speed to outspeed weavile at +1.  Atk hits a jump point and allows you to 2 hit KO offensive mega altaria at +1, and gives a roll two hit KO defensive mega altaria after rocks at +1.  Bulk takes a specs Latios draco meteor from full as well as a banded weavile's knock off after rocks.  Lum is preferred over an item such as lefties so that you can threaten rotom more and switch into scalds from keldeo etc.