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You have nothing to handle steel types like Ferrothorn, Scizor, Skarmory. Get some fire types, or use a mixed Dragonite with Flamethrower (Dragon Dance, Dragon Claw, Extreme Speed, wear a weakness policy).
Stealth Rocks? Try Mamoswine or Tyranitar.
Good job on Togekiss. Shuts down most Mega Venusaurs (most don't pack poison moves but prefer Earthquake).
If you want to be a bit more annoying, I'd fit in Espeon. Magic Bounce some hazards/status/whirlwinds and calm mind/baton pass some boosts to make Togekiss or Blastoise harder to take down. Or sweep with Espeon if you can (use Psychic). Wish passing is awesome, too.
So consider:
Dragonite
Tyranitar/Mamoswine/Espeon
You might not even need to pack rocks if you can predict correctly with Espeon.