Check:
Camerupt @ Cameruptite
Ability: Solid Rock
EVs: 252 HP / 252 Spa / 4 SpD
Modest Nature
- Fire Blast
- Earth Power
- Stealth Rock
- Ancient Power / HP Ice
Rupt Mega, not exactly your daily SR Setter, nor mega, but still checks LO/Lefties Thundy-T.
He can't switch into LO Focus Blast, but can take any hit once & OHKO back with Fire Blast:
252+ SpA Life Orb Thundurus-T Focus Blast vs. 252 HP / 0 SpD Mega Camerupt: 194-229 (56.3 - 66.5%) -- guaranteed 2HKO
252+ SpA Sheer Force Mega Camerupt Fire Blast vs. 4 HP / 0 SpD Thundurus-T: 337-397 (112.7 - 132.7%) -- guaranteed OHKO
Nothing else to say, it's just Rupt Mega.
Camerupt @ Cameruptite
Ability: Solid Rock
EVs: 252 HP / 252 Spa / 4 SpD
Modest Nature
- Fire Blast
- Earth Power
- Stealth Rock
- Ancient Power / HP Ice
Rupt Mega, not exactly your daily SR Setter, nor mega, but still checks LO/Lefties Thundy-T.
He can't switch into LO Focus Blast, but can take any hit once & OHKO back with Fire Blast:
252+ SpA Life Orb Thundurus-T Focus Blast vs. 252 HP / 0 SpD Mega Camerupt: 194-229 (56.3 - 66.5%) -- guaranteed 2HKO
252+ SpA Sheer Force Mega Camerupt Fire Blast vs. 4 HP / 0 SpD Thundurus-T: 337-397 (112.7 - 132.7%) -- guaranteed OHKO
Nothing else to say, it's just Rupt Mega.