STAB Extremespeed coming off of Arceus, especially with Silk Scarf at +2, will definitely hurt. I'm using Kyurem White on my Sun team, as 170 Base Special Attack = win.
Sunny Days Above!
Landslide (Groudon) @ Leftovers
EVs: 252 HP / 4 Atk / 252 Def
- Stealth Rock
- Stone Edge
- Dragon Tail
Groudon. The Patron of the Land Sector. A great Physical wall. What else? It can take +2 Outrages from Garchomp, +2 Dragon Claws from Rayquaza, and even +2 Close Combats from Terrakion and Lucario. It then uses Earthquake on them, or Stone Edges them. Stealth Rock is almost mandatory for this Pokémon, because hazards are needed in almost every match. Earthquake is STAB, and nails nearly everything not Flying type/Levitating. Which Stone Edge then hits, bar Bronzong, who rarely comes in anyway. Dragon Tail is there to have some switching going on- I never use Thunder Wave anyway and I only abuse Toxic when Protect and/or Substitute is in play.
Frost2Fire (Kyurem- W) @ Choice Specs
EVs: 4 HP / 252 SpA / 252 Spe
- Draco Meteor
- Ice Beam
- Fusion Flare
- Focus Blast
Specs Kyurem White definitely hurts, with base 170 Special Attack. 95 Speed isn't bad either; it's faster than the weather trio, and is also faster than Zekrom and possibly Reshiram. This thing can 2HKO Kyogre! Draco Meteor is like Latios' in OU- Spam it and things die. Well, sort of. Ice Beam hits other Pokémon for some decent damage as well, especially when you don't want to weaken your Special Attack. Fusion Flare is boosted in Sun, and does a decent chunk of damage. Focus Blast is for other Steel types like Heatran, who resists every other move on this set.