Stall Tornadus
Tornadus-Therian (M) @ Leftovers
Ability: Regenerator
EVs: 252 HP / 88 Def / 168 Spe
Timid Nature
IVs: 0 Atk
- Foul Play
- Defog
- Heat Wave
- U-turn
This set can fit on stall, but you need a bit of luck for it to check offensive Heatran. Magma Storm has trash accuracy and low pp, meaning you can abuse regenerator to stall out pp for Magma Storm. U-turn let's you switch out if you get hit by Magma Storm, and switch to something else, like Sableye (which can't be trapped in virtue of its typing).
Anywho, the given speed investment allows you to outspeed base 110s. The defense investment allows you to avoid the OHKO from Kartana's unboosted Breakneck Blitz. Heat Wave OHKOs Kartana, and has more accuracy than hurricane. Speed boosting Blace fails to OHKO with its z move, and is 2HKOed by foul play (OHKOed after rocks). Blace without hp/def investment is OHKOed by foul play.
Torn can also serve as a soft check to Gren (and can defog spikes, unlike Chansey) and banded Bulu. You'll want to scout for what move they lock into first, if possible. You can use charti berry to ease this somewhat, in which case you can check rockium Lando and Garchomp. This means you can use something other than Zapdos or Avalugg as your other hazard remover, like mew, which can better check Heatran.