Had some success with this team but there's still a lot of work to be done with it, so maybe you guys can help.
Brongzong@Shed Shell
Sassy : 252 HP, 120 Atk, 128 Def, 8 Sp. Def
Levitate
-Hypnosis
-Stealth Rock
-Gyroball
-Explosion
The usual overused lead. Sets up stealth rock, hypnotizes something, then blows up either scoring a KO or putting a dent in whatever it was facing. I don’t know if it’s just me, but lately it’s been a liability as I’ve seen several Heatran, Gallade, and Gyarados leads. I often have to use Gyroball over Stealth Rock. Choice of items is kind of strange but I’d rather not face an immune to ground Magnezone sitting behind a sub, down a pokemon.
Jirachi@Leftovers
Relaxed : 240 HP, 56 Atk, 76 Def, 136 Sp. Def
Serene Grace
-Wish
-Zen Headbutt
-U-Turn
-Thunder
When I don’t know what I want to do, I usually go to this guy, probably the most important member of the team. Jirachi brings the Wish support which Brongzong really likes, and helps combat the effects of Stealth Rock on my fliers. Zen Headbutt for Gengar, Tentacruel, and Heracross, U-Turn to switch out, and Thunder for Gyarados, almost always an OHKO if it hits and Jirachi is bulky enough to take a DDed Earthquake as long as there is no life orb. The EV spread is kind of a mess, I took the ones on the analysis, played around with them a bit and changed the nature. With a minus Sp.Atk, Thunder needs Stealth Rock up to OHKO and the minus Spd nature helps when I U-Turn out and want Jirachi to take the hit. Maybe I should go Psychic over Zen Headbutt and allocate the Atk EVs elsewhere?
Salamence@Life Orb
Naïve : 80 Atk, 176 Spd, 252 Sp.Atk
Intimidate
-Draco Meteor
-Flamethrower
-Brick Break
-Roost
Mixmence is the most versatile pokemon on the team, Draco Meteor being his primary attack which is even more threatening given the declining usage of Blissey. Flamethrower for more accuracy since I’ve never really needed the extra power of Fire Blast. Brick Break for Blissey and Heatran. With the attack EVs, it can usually 2HKO Blissey, guaranteed of Stealth Rock is up. Maybe a +Sp.Atk would serve me better, but I like being faster than the usual base 100s.
Mamoswine@Choice Band
Adamant : 4 HP, 252 Atk, 252 Spd
Snow Cloak
-Earthquake
-Ice Shard
-Ice Fang
-Stone Edge
When I was first drawing up this team, I threw this guy on just to try and keep Garchomp in check but after using him a few times, I realized that he does so much more. A pretty good revenge killer with Ice Shard and STAB Earthquake does a ton of damage. Max speed to win ties or beat other Mamoswines. An idea I was toying with was Scarving him and using Ice Fang primarily over Ice Shard, as it would deal slightly more damage. However, I’m reluctant to lose that extra power on Earthquake
Lucario@Life Orb
Adamant: 4 HP, 252 Atk, 252 Spd
Inner Focus
-Close Combat
-Extremespeed
-Bullet Punch
-Swords Dance
Lucario is such a powerhouse, and I think (probably erroneously) with a Swords Dance up that its more dangerous than even Garchomp. Pretty standard set with Bullet Punch over Crunch and Stone Edge as I’m more worried about it taking on Gengar than Gyarados, Cresselia, Dusknoir.
Gyarados@Leftovers
Adamant: 212 HP, 16 Atk, 176 Def, 104 Spd
Intimidate
-Waterfall
-Earthquake
-Ice Fang
-Dragon Dance
I originally had Togekiss in this slot but using this team a few times made me realize my huge Heatran/Infernape weak. I tried using Scarftran but its not really a reliable Heatran counter so I slapped Gyarados on the team as my Band-Aid solution. However, I still risk Lava Plume burns if its Resttalk, and Stealth Rock severely limits my switch-ins. I want to stick taunt somewhere, but not sure which move to replace. Ice Fang has to stay as its another check on Garchomp, and I like Waterfall for the damage. I put Earthquake on mostly because I use Jirachi as a Gyarados counter and its really effective as long as it doesn’t have Earthquake, so that biased me to have something to deal with Jirachi. Also helps a little against Suicune and Vaporeon.
The most glaring flaw in this team is still the Heatran weak. I’m thinking of swapping Brongzong out for Swampert, but it means losing Hypnosis which I’m loathe to do. Looking for some input on how to deal with that. This team doesn’t like Thunderpunching Metagross that much either.

Brongzong@Shed Shell
Sassy : 252 HP, 120 Atk, 128 Def, 8 Sp. Def
Levitate
-Hypnosis
-Stealth Rock
-Gyroball
-Explosion
The usual overused lead. Sets up stealth rock, hypnotizes something, then blows up either scoring a KO or putting a dent in whatever it was facing. I don’t know if it’s just me, but lately it’s been a liability as I’ve seen several Heatran, Gallade, and Gyarados leads. I often have to use Gyroball over Stealth Rock. Choice of items is kind of strange but I’d rather not face an immune to ground Magnezone sitting behind a sub, down a pokemon.

Jirachi@Leftovers
Relaxed : 240 HP, 56 Atk, 76 Def, 136 Sp. Def
Serene Grace
-Wish
-Zen Headbutt
-U-Turn
-Thunder
When I don’t know what I want to do, I usually go to this guy, probably the most important member of the team. Jirachi brings the Wish support which Brongzong really likes, and helps combat the effects of Stealth Rock on my fliers. Zen Headbutt for Gengar, Tentacruel, and Heracross, U-Turn to switch out, and Thunder for Gyarados, almost always an OHKO if it hits and Jirachi is bulky enough to take a DDed Earthquake as long as there is no life orb. The EV spread is kind of a mess, I took the ones on the analysis, played around with them a bit and changed the nature. With a minus Sp.Atk, Thunder needs Stealth Rock up to OHKO and the minus Spd nature helps when I U-Turn out and want Jirachi to take the hit. Maybe I should go Psychic over Zen Headbutt and allocate the Atk EVs elsewhere?

Salamence@Life Orb
Naïve : 80 Atk, 176 Spd, 252 Sp.Atk
Intimidate
-Draco Meteor
-Flamethrower
-Brick Break
-Roost
Mixmence is the most versatile pokemon on the team, Draco Meteor being his primary attack which is even more threatening given the declining usage of Blissey. Flamethrower for more accuracy since I’ve never really needed the extra power of Fire Blast. Brick Break for Blissey and Heatran. With the attack EVs, it can usually 2HKO Blissey, guaranteed of Stealth Rock is up. Maybe a +Sp.Atk would serve me better, but I like being faster than the usual base 100s.

Mamoswine@Choice Band
Adamant : 4 HP, 252 Atk, 252 Spd
Snow Cloak
-Earthquake
-Ice Shard
-Ice Fang
-Stone Edge
When I was first drawing up this team, I threw this guy on just to try and keep Garchomp in check but after using him a few times, I realized that he does so much more. A pretty good revenge killer with Ice Shard and STAB Earthquake does a ton of damage. Max speed to win ties or beat other Mamoswines. An idea I was toying with was Scarving him and using Ice Fang primarily over Ice Shard, as it would deal slightly more damage. However, I’m reluctant to lose that extra power on Earthquake

Lucario@Life Orb
Adamant: 4 HP, 252 Atk, 252 Spd
Inner Focus
-Close Combat
-Extremespeed
-Bullet Punch
-Swords Dance
Lucario is such a powerhouse, and I think (probably erroneously) with a Swords Dance up that its more dangerous than even Garchomp. Pretty standard set with Bullet Punch over Crunch and Stone Edge as I’m more worried about it taking on Gengar than Gyarados, Cresselia, Dusknoir.

Gyarados@Leftovers
Adamant: 212 HP, 16 Atk, 176 Def, 104 Spd
Intimidate
-Waterfall
-Earthquake
-Ice Fang
-Dragon Dance
I originally had Togekiss in this slot but using this team a few times made me realize my huge Heatran/Infernape weak. I tried using Scarftran but its not really a reliable Heatran counter so I slapped Gyarados on the team as my Band-Aid solution. However, I still risk Lava Plume burns if its Resttalk, and Stealth Rock severely limits my switch-ins. I want to stick taunt somewhere, but not sure which move to replace. Ice Fang has to stay as its another check on Garchomp, and I like Waterfall for the damage. I put Earthquake on mostly because I use Jirachi as a Gyarados counter and its really effective as long as it doesn’t have Earthquake, so that biased me to have something to deal with Jirachi. Also helps a little against Suicune and Vaporeon.
The most glaring flaw in this team is still the Heatran weak. I’m thinking of swapping Brongzong out for Swampert, but it means losing Hypnosis which I’m loathe to do. Looking for some input on how to deal with that. This team doesn’t like Thunderpunching Metagross that much either.