Rotom-Wash @ Leftovers 
Ability: Levitate 
EVs: 252 HP / 252 Def / 4 SpD 
Bold Nature 
IVs: 0 Atk / 30 Spe 
- Defog 
- Volt Switch 
- Hydro Pump 
- Pain Split 

Moltres @ Flyinium Z 
Ability: Flame Body 
EVs: 4 Def / 252 SpA / 252 Spe 
Timid Nature 
- Hurricane 
- Fire Blast 
- Roost 
- U-turn 

Serperior @ Leftovers 
Ability: Contrary 
EVs: 4 HP / 252 SpA / 252 Spe 
Timid Nature 
IVs: 0 Atk 
- Defog 
- Leaf Storm 
- Dragon Pulse 
- Hidden Power [Fire] 

Scizor @ Choice Band 
Ability: Technician 
EVs: 248 HP / 252 Atk / 8 SpD 
Adamant Nature 
- U-turn 
- Bullet Punch 
- Superpower 
- Pursuit 

Altaria-Mega @ Altarianite 
Ability: Pixilate 
Happiness: 0 
EVs: 252 HP / 80 Def / 176 Spe 
Impish Nature 
- Dragon Dance 
- Frustration 
- Roost 
- Heal Bell 

Hippowdon @ Leftovers 
Ability: Sand Stream 
EVs: 252 HP / 80 Def / 176 SpD 
Impish Nature 
- Stealth Rock 
- Stone Edge 
- Earthquake 
- Slack Off

I wanted two things:
- Use Moltres
- Slap as many potential Defoggers as I could in one team, while making sure it isn't cheesy and works vs competent players
Moltres is the star of the team, hits pretty hard (Z-Hurricane is amazing) and it's surprisingly hard to check thanks to the combination of power and U-turn. Rotom-W has amazing synergy with Moltres, as it checks some Water-types that threaten it, removes rocks, and many of the things that don't mind Volt Switch are Moltres bait. Serperior is the backup Defogger, can pull off sweeps vs some teams once the rest of the team weakens the foe's team, and it really enjoys getting free switch ins thanks to Voltturn. Scizor is standard in teams like this, checks tons of shit, wrecks shit with U-turn and has solid offensive synergy with Moltres and Rotom-W. Mega Altaria patches a bunch of holes, provides Heal Bell support (Refresh is usually the preferred option, but the team isn't based around Altaria), and if you face one of the shitty teams that rely on Scizor to not get swept by this, they pretty much can't click U-turn once against anything because Moltres is Flame Body. I wanted a SR user, soft Aerodactyl check, hard Manetric / Raikou counter, and I didn't want to use Swampert because it's easier to chip down.
Team isn't anything amazing, but it has been extremely reliable vs good players so far. ftr I like my slow Volturners to punish the mirror matchup and I don't need to speed creep with them on this team.