I've been working on this team for a few weeks, and I find the end result to be pretty decent. Check it out.
Gyarados @ Leftovers
Adamant, 212 HP/16 Atk/136 Def/144 Spe
Taunt
Stone Edge
Waterfall
Dragon Dance
My starter. Gotta love this dude. Stone Edge+Waterfall=good coverage.
Lucario @ Choice Specs
Modest, 252 SpA/252 Spe/4 Def
Vaccum Wave
Aura Sphere
HP Ice
Dark Pulse
Gotta love good old SpecsLuke. Probably my best bet against the pink whore.
Fortress @ Shed Shell
Relaxed, 252 Def/216 HP/40 SpA
Toxic Spikes
Rapid Spin
Zap Cannon
Stealth Rocks
My spiker/spinner. The only unorthodox thing about this is Zap Cannon, which helps cover Gyara if it gets a DD or two in. Since I no longer have Blissey to lay down rocks, I put them on Forry. Vaporeon can give wish support in place of Rest.
Cresselia @ Leftovers
Modest, 252 Def/20 HP/236 SpA
Reflect
Ice Beam
Moonlight
Thunder Wave/Charge Beam
Cresselia can provide some Reflect support, which my team can put to awesome use. I opt for Moonlight over Rest because although I have no way to change the weather, I don't have a Cleric to wake up Cress. I like Thunder Wave over Charge beam because Fortress already has Zap Cannon, and TWave can help pick off faster sweepers.
Snorlax @ Choice Band
Adamant, Thick Fat, 252 Atk/252 SpD/4 HP
Body Slam
Earthquake
Fire Punch
Selfdestruct
As I was looking over my team, I thought to myself two things: What will I use for physical muscle if Gyara faints? and I need something that can pack a punch and take a hit or two. So I decided to swap out my ScarfStar for a CBlax. I still have some reservations about this spot, though. I have been debating between CBlax, Resttalking Snorlax, and Dusclops. So far, I like this Snorlax. I prefer Fire Punch over Fire Blast because Punch hits Gengar and co. harder while still doing decent damage to Skarmory.
Vaporeon @ Leftovers
Bold, 252 Def/48 Spe/206 HP
Wish
Surf
Toxic
Protect/Yawn
Vaporeon provides my much needed wish support. I put most of the EVs that normally go into Special Attack into Speed, and the rest into HP. I don't need the SpA EVs for Ice Beam because Cresselia already can OHKO Garchomp. Protect works in tandem with Toxic and Leftovers, helps scout moves and possibly cause switches. Yawn can either cause switches or put an opponent out of business.
I like this team. Vaporeon, Fortress, and Cresselia work well, providing Wish and Toxic support, Spikes, Stealth Rocks and Spin support, and Reflect and TWave support. As I mentioned, Relfect can really benefit my team, making Vaporeon and Snorlax harder to take down, letting Lucario take even less damage from Rock and Dark attacks, and Gyarados to switch into Heracross more frequently. Snorlax has always been one of my favorite pokemon, and I always hated facing him because he is a monster. I guess Resttalking Snorlax could benefit from Reflect even more, but I really like the raw power that a CBlax offers. I love Lucario, I just wish he was faster though. His raw power makes up for it though.
I think that adding Vaporeon and Cresselia covers some of the weaknesses that I had before, and those two combined with Fortress make a great defensive combo. But an outside opinion would be awesome.

Gyarados @ Leftovers
Adamant, 212 HP/16 Atk/136 Def/144 Spe
Taunt
Stone Edge
Waterfall
Dragon Dance
My starter. Gotta love this dude. Stone Edge+Waterfall=good coverage.

Lucario @ Choice Specs
Modest, 252 SpA/252 Spe/4 Def
Vaccum Wave
Aura Sphere
HP Ice
Dark Pulse
Gotta love good old SpecsLuke. Probably my best bet against the pink whore.

Fortress @ Shed Shell
Relaxed, 252 Def/216 HP/40 SpA
Toxic Spikes
Rapid Spin
Zap Cannon
Stealth Rocks
My spiker/spinner. The only unorthodox thing about this is Zap Cannon, which helps cover Gyara if it gets a DD or two in. Since I no longer have Blissey to lay down rocks, I put them on Forry. Vaporeon can give wish support in place of Rest.

Cresselia @ Leftovers
Modest, 252 Def/20 HP/236 SpA
Reflect
Ice Beam
Moonlight
Thunder Wave/Charge Beam
Cresselia can provide some Reflect support, which my team can put to awesome use. I opt for Moonlight over Rest because although I have no way to change the weather, I don't have a Cleric to wake up Cress. I like Thunder Wave over Charge beam because Fortress already has Zap Cannon, and TWave can help pick off faster sweepers.

Snorlax @ Choice Band
Adamant, Thick Fat, 252 Atk/252 SpD/4 HP
Body Slam
Earthquake
Fire Punch
Selfdestruct
As I was looking over my team, I thought to myself two things: What will I use for physical muscle if Gyara faints? and I need something that can pack a punch and take a hit or two. So I decided to swap out my ScarfStar for a CBlax. I still have some reservations about this spot, though. I have been debating between CBlax, Resttalking Snorlax, and Dusclops. So far, I like this Snorlax. I prefer Fire Punch over Fire Blast because Punch hits Gengar and co. harder while still doing decent damage to Skarmory.

Vaporeon @ Leftovers
Bold, 252 Def/48 Spe/206 HP
Wish
Surf
Toxic
Protect/Yawn
Vaporeon provides my much needed wish support. I put most of the EVs that normally go into Special Attack into Speed, and the rest into HP. I don't need the SpA EVs for Ice Beam because Cresselia already can OHKO Garchomp. Protect works in tandem with Toxic and Leftovers, helps scout moves and possibly cause switches. Yawn can either cause switches or put an opponent out of business.
I like this team. Vaporeon, Fortress, and Cresselia work well, providing Wish and Toxic support, Spikes, Stealth Rocks and Spin support, and Reflect and TWave support. As I mentioned, Relfect can really benefit my team, making Vaporeon and Snorlax harder to take down, letting Lucario take even less damage from Rock and Dark attacks, and Gyarados to switch into Heracross more frequently. Snorlax has always been one of my favorite pokemon, and I always hated facing him because he is a monster. I guess Resttalking Snorlax could benefit from Reflect even more, but I really like the raw power that a CBlax offers. I love Lucario, I just wish he was faster though. His raw power makes up for it though.
I think that adding Vaporeon and Cresselia covers some of the weaknesses that I had before, and those two combined with Fortress make a great defensive combo. But an outside opinion would be awesome.