Heatran @ Leftovers
Ability: Flash Fire
EVs: 248 HP / 40 Def / 220 SDef
- Lava Plume
- Stealth Rock
My first instinct when Aurumoth was picked was to add Defensive Heatran to the team.
First off, having Rocks on the field helps any offensive position to pull off a quicker sweep. Toxic also helps our sweepers, and Steel types that resist poisoning don't want to take a Lava Plume even if unboosted.
Secondly, Aurumoth hates Fire and Rock moves, which Heatran can take if you can't take the sweep.
Additionally, because Aurumoth has Blizzard, it can take Colossoil, a major threat to Heatran in that it can bounce back Rocks.
This set allows Heatran to survive both physical hits (mainly Pursuit from Colossoil because we don't want to be 1v1 with it) and special moves from opposing Special Aurumoth and Tomohawk.