One thing which might work if he winds up in UU or lower is a pseudo-Skarmory:
Tyrantrum - Impish - 252 HP, 252 Def, 4 Atk
Item: Leftovers
- Stealth Rock
- Dragon Tail
- Earthquake / Fire Fang / Ice Fang / Thunder Fang / Hone Claws
- Stone Edge / Head Smash / Ice Fang / Thunder Fang / Poison Fang
I invest in Def over SpD because you're not taking any hits on the special end even if it was invested.
Stealth Rock is self-explanatory. Dragon Tail shuffles with STAB as it does so -- with Stealth Rock damage, it's going to hurt, especially coming off of that Attack.
Earthquake and Stone Edge / Head Smash form the lovely EdgeQuake combo. Fire Fang is an option instead of EQ for the 10% chance to burn (considering the difference in BP between the two is negligible with Strong Jaw). Ice Fang / Thunder Fang can form the BoltBeam combo, but Ice Fang gets slightly redundant coverage with Dragon Tail. Hone Claws boosts the power of Dragon Tail and gets rid of its 90% accuracy. Poison Fang is an option for Fairies and the 30% chance for Toxic Poison, but should always be run with EQ or Fire Fang as a way to hit Steels.
The main problem with this set is the fact that you can accidentally shuffle in a Special Attacker, which forces you to switch. You also have no recovery outside of Leftovers and possibly Rest. These hold it back in the higher tiers when compared to Skarmory, but if he does become UU or lower it could perform Skarmory's function quite well.
E: Another option:
Tyrantrum - Jolly - 252 Atk, 252 Spe, 4 HP
Item: Leftovers
- Dragon Dance
- Head Smash / Crunch / Ice Fang / Dragon Claw
- Rest
- Sleep Talk
This works similar to the famous CroCune, but swapping Speed for Special Defense boosts. The idea is you come in on someone you can set up on and Dragon Dance on the switch. You can use Rest to keep yourself healthy, and Sleep Talk to either boost further or demolish your opponent. Which attacking move you use depends on your personal choice -- Head Smash for raw damage, Crunch becomes a 120 BP move with no immunities, Ice Fang becomes an Ice-Type EQ with a chance to freeze, and Dragon Claw works as a second STAB option.