Here is my favorite Thundurus-T set:
Thundurus-Therian (M) @ Expert Belt
Trait: Volt Absorb
EVs: 4 Atk / 252 SAtk / 252 Spd
Naive Nature
- Thunder
- U-turn
- Hidden Power [Ice]
- Superpower
Mixed Thundurus-T is an excellent wallbreaker and i don't get why so few people use it. This beast is walled by only two Pokemon in OU, Ferrothorn and Gastrodon, and Ferrothorn is easy to wear down and takes 41.47 - 49.14% from Superpower. U-turn allows Thundurus-T to scout Ground-type switch-ins, and beat three of its most common switch-ins, Latios, Latias, and Celebi. Here are calcs of U-turn against those three:
- 4 Atk Expert Belt Thundurus-T U-turn vs. 252 HP / 0 Def Celebi: 254-302 (62.87 - 74.75%) -- guaranteed 2HKO
- 4 Atk Expert Belt Thundurus-T U-turn vs. 4 HP / 0 Def Latios: 154-182 (50.99 - 60.26%) -- guaranteed 2HKO
- 4 Atk Expert Belt Thundurus-T U-turn vs. 252 HP / 0 Def Latias: 139-166 (38.18 - 45.6%) -- Always 2HKOes followed by HP Ice with SR up
Not only this, but U-turn build up damage to other common switch-ins to Thundurus-T, such as Mamoswine, Chansey, and SpD Hippowdon. Mamoswine is OHKOed by Superpower after a U-turn with SR up, Chansey is 2HKOed by Superpower after taking a U-turn with SR up, and SpD Hippowdon is 2HKOed by HP Ice after taking a U-turn with SR up. Blissey is easily 2HKOed by Superpower even without SR up. Superpower also always OHKOes 252 HP Tyranitar and has perfect accuracy unlike the god awful Focus Blast, which makes me want to hit my head in the wall every time i have to depend on it. All in all this is a great set that needs more love and solves most of Thundurus-T's problems (low accuracy of Focus Blast, SR + LO build up fast, Volt Switch blocked by Ground-types on choiced sets, Celebi walls most other Thundurus-T sets and the same is true for Chansey and Blissey).
Choice Band Scizor with Pursuit is an excellent partner to this set as it can trap and kill Lati@s and deal with every other Pokemon that would want to switch into Thundurus-T, OHKOing Ferrothorn and getting momentum against Gastrodon.