Latias (F) @ Leftovers
EVs: 4 Def / 252 HP / 252 Spd
- Calm Mind
- Dragon Pulse
- Reflect Type
Mmmk, meet Reflect Type Latias.
Why Reflect type? Well, you know how CM Latias always gets destroyed by TTar? Not this CM Latias. Reflect Type gives Latias the same typing as TTar, meaning it becomes Rock/Dark and resists his Pursuit/Crunch, can Recover off the damage and then continue to CM.
CM Latias also gives you a handy Steel/Grass typing against rain teams with Ferrothorn, who can only TWave Latias.
Latias can already have a field day against Sun Teams, with Reflect type it can easily set up on it's supposed-to-be counters in Sand offense (TTar) and rain whatever (Ferrothorn), meaning it can deal with a lot of weather teams and be on any type of weather team.
252+ Atk Choice Band Tyranitar Crunch vs. 252 HP / 4 Def Latias: 120-141 (32.96 - 38.73%) -- 7.62% chance to 3HKO
252+ Atk Choice Band Scizor U-turn vs. 252 HP / 4 Def Latias: 102-121 (28.02 - 33.24%) -- possible 4HKO
You get bulk, nice counters to weather teams, and can beat it's 'counters'.
Building a team around it could be pretty neat, you can get some Pokes that remove some annoying Pokemon and still have a decent team.