Mamoswine (M) @ Choice Scarf
Trait: Thick Fat
IVs: 31 HP / 31 Atk/ 31 Def/ 1 SAtk / 31 SDef / 31 Spd
EVs: 124 HP / 44 Atk / 100 Def / 44 SDef / 196 Spd
Adamant Nature (+Atk, -SAtk)
– Icicle Spear
– Earthquake
– Icicle Crash
– Rock Slide
Felt like I had something still to add
This is Arash Ommati VGC 2013 Masters winning Mamoswine set. Immune to T Wave, outspeeds Thundy, outspeeds base Lando-T (prior to scarf, but they ain't staying in) and so on. Although it's a little dated, you could probably try it in the current meta