I'll like to note that if there's a need to, a fine tuning step can be done at the end where all 6 Pokemon are selected; it will be a step for minor changes only, ie no major change like changing the Pokemon.jorgen as long as the sets are flexible
Celebi @ Leftovers
Natural Cure
240 HP / 224 Def / 44 Spe
Bold Nature
- Calm Mind
- Leech Seed
- Recover
- Giga Drain / HP Grass
Can boost along with Cune, or Leech Seed it. It does also Leech Seed and boost on Snorlax, who could be a major nuisance because he can come on Moltres and start Cursing.
The issue now, can be stuff like DD Ttar that could also set-up on Moltres (and switch the weather by the way) and hit everybody for good damages. Aerodactyl would be also annoying I guess given the coverage.
So I'm gonna take 0 risk and go for :
Swampert @ Leftovers
Torrent
240 HP / 32 SpA / 32 Atk / 16 Spe / 188 Def
Relaxed Nature
- Toxic
- Protect
- Earthquake
- Ice Beam
Classic Swampert, he will wall the stuff that I mentioned (and Gyarados that I forgot !) and cripple bulky waters with Toxic. Nothing special here.
Dugtrio (M) @ Choice Band
Trait: Arena Trap
EVs: 8 HP / 208 Atk / 40 SDef / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Aerial Ace
- Earthquake
- Hidden Power [Bug]
- Rock Slide
+
Suicune @ Leftovers
Trait: Pressure
EVs: 252 HP / 96 SAtk / 160 Spd
Modest Nature (+SAtk, -Atk)
- Calm Mind
- Surf
- Substitute
- Ice Beam
As Jorgen previously mentioned, Dugtrio traps a lot of Moltres' counters. Suicune might be a good fit because it sets up on the bulky waters that Moltres has trouble with if Metagross cant boom on them. Defensively, this core in addition to the rest of our team covers a majority of ADV. if we use my suggestion we'll need to really pack good answers to electric-types and snorlax.
Gengar @ Leftovers
Trait: Levitate
EVs: 40 Atk / 216 SpA / 252 Spe
Hasty Nature
- Thunderbolt
- Ice Punch
- Explosion
- Hypnosis / Will-O-Wisp / Hidden Power [Water] / Focus Punch
Dugtrio @ Choice Band
Trait: Arena Trap
EVs: 4 HP / 252 Atk / 252 Spe
Jolly or Adamant
- Earthquake
- Rock Slide
- Hidden Power [Bug]
- Aerial Ace
Gengar lures in all the problematic mons that Jorgen listed (Snorlax, Blissey, Houndoom, Tyranitar) so that they can be severely crippled or killed by either Gengar or Dugtrio. Gengar can Explode on the special sponges that swithes in, whereas it can sac itself or double-switch into Dugtrio versus Tyranitar or Houndoom.
The last moveslot for Gengar is largely filler, with handful of options. HP Water or Focus Punch are both legitimate options in softening up or knocking out the Dark-types, but the status moves are useful overall.