Something I quickly made up was
Jaroda @ Life Orb
Timid Nature (+Spd, -Atk)
Ability: Contrarian
EVs: 16 Def / 252 Sp. Atk / 236 Spd
- Calm Mind
- Leaf Storm
- Synthesis
- Hidden Power: Ground
Calm Mind once and hit with Leaf Storm, which if I've read right will increase your Special Attack to +3. HP:Ground over HP:Fire as Heatran will likely be the first switch in to this pokemon, and a +3 Leaf Storm will do a lot of damage to things that only 2x resist it (next time it'll be on +5). Synthesis is just there to heal up, and Jaroda has got the bulk to take a hit or two even with minimal defensive EV investment. Speaking of which, Calm Mind boosts that decent 95 Sp. Defence up a stage. The last 16 EVs give it more bulk on the physical side.
I'm not sure if Jaroda will compete with like the likes of Warubiaru and and Sazando, but in a lower tier I can definitely see it becoming a threat.