Goal is to set up Stealth Rock with Swampert, then sweep through the rest of the opponent's team while throwing in a little bit of Para-burns.
Swampert @ Leftovers
Torrent
Relaxed nature (+Def/-Spd)
252 HP/4 Atk/252 Def
-Earthquake
-Stealth Rock
-Ice Beam
-Roar
-Replaces Hippowdon- Lead. Stealth Rock is a team-support must for this set, Earthquake for a powerful STAB, Ice Beam takes out Dragons, Roar for PHazing.
Gengar!!! @ Life Orb
Levitate
Naive nature (+Spd/-SpD)
4 Atk/252 Spd/252 SpA
-Shadow Ball
-Thunderbolt
-Explosion
-Focus Blast
Special sweeper. After Stealth Rock is in play, everything on the opponent's team gets easier to kill, especially with this little guy. Shadow Ball is an effective STAB move that can remove annoying Rotoms and Dusknoirs, provided it isn't hit first. Focus Blast will always OHKO Tyranitar and Weavile, if it hits. T-Bolt is good to fall back on when faced with waters, especially Gyarados. If things get tough, it can always blow itself up for an almost guaranteed kill.
Celebi @ Life Orb
Natural Cure
Modest (+SpA/-Atk)
232 HP/32 Spd/244 SpA
-HP Fire
-Leaf Storm
-Thunder Wave
-Rest
Annoying. Celebi can easily use T-Wave to compensate for its below-average speed(243), then beat the opponent down with HP fire (Steels, Grasses, things that resist grass attacks) and Leaf Storm. I might swap Leaf Storm for Energy Ball. Leaf Storm works out OK because It'll be switching out anyway to cure its sleep. Rest will restore its HP to full, then a switch-out will remove the sleep AND the SpA drops.
Jolteon @ Leftovers
Volt Absorb
Timid (+Spd/-Atk)
4 HP/252 Spd/252 SpA
-Charge Beam
-Thunderbolt
-Shadow Ball
-HP Grass
-Redone Set- Easily takes out Pert and grounds (save for Gliscor) with HP Grass. Thunderbolt for a powerful & accurate STAB, Charge Beam to raise SpA, and Shadow Ball is pretty much its only other special attacking option. Timid/Max speed EVs leaves it with a huge 394, outspeeding pretty much everything else.
Infernape @ Life Orb
Blaze
Jolly (+Spd/-SpA)
64 HP/252 Atk/192 Spd
-Fire Punch
-Close Combat
-Stone Edge
-Swords Dance
Excellent physical sweeper. Boosts its Atk with Swords Dance, then sweeps through the opponent's team. Very simple. However, it's sometimes countered by faster Infernapes with Earthquake, resulting in a OHKO.
Rotom-C @ Leftovers
Levitate
Timid (+Spd/-Atk)
252 HP/68 Def/188 Spd
-Thunderbolt
-Shadow Ball
-Will-o-Wisp
-Substitute
WoW'er/Staller. Easily sets up burns with WoW, then Substitute. Pert gets scared off by a potential Leaf Storm, and ghosts and waters are easily defeated by its attacks.
There you go.
I have noticed some weak points on my own, I've overused Electric and Ghost attacks. If gravity gets in play, then I'll get destroyed by ground attacks. A special wall is horrible to encounter if Infernape is already dead, as I don't expect Swampert to do anything super-special.
[Credit for pics to Deviantart users]


Swampert @ Leftovers
Torrent
Relaxed nature (+Def/-Spd)
252 HP/4 Atk/252 Def
-Earthquake
-Stealth Rock
-Ice Beam
-Roar
-Replaces Hippowdon- Lead. Stealth Rock is a team-support must for this set, Earthquake for a powerful STAB, Ice Beam takes out Dragons, Roar for PHazing.

Gengar!!! @ Life Orb
Levitate
Naive nature (+Spd/-SpD)
4 Atk/252 Spd/252 SpA
-Shadow Ball
-Thunderbolt
-Explosion
-Focus Blast
Special sweeper. After Stealth Rock is in play, everything on the opponent's team gets easier to kill, especially with this little guy. Shadow Ball is an effective STAB move that can remove annoying Rotoms and Dusknoirs, provided it isn't hit first. Focus Blast will always OHKO Tyranitar and Weavile, if it hits. T-Bolt is good to fall back on when faced with waters, especially Gyarados. If things get tough, it can always blow itself up for an almost guaranteed kill.

Celebi @ Life Orb
Natural Cure
Modest (+SpA/-Atk)
232 HP/32 Spd/244 SpA
-HP Fire
-Leaf Storm
-Thunder Wave
-Rest
Annoying. Celebi can easily use T-Wave to compensate for its below-average speed(243), then beat the opponent down with HP fire (Steels, Grasses, things that resist grass attacks) and Leaf Storm. I might swap Leaf Storm for Energy Ball. Leaf Storm works out OK because It'll be switching out anyway to cure its sleep. Rest will restore its HP to full, then a switch-out will remove the sleep AND the SpA drops.

Jolteon @ Leftovers
Volt Absorb
Timid (+Spd/-Atk)
4 HP/252 Spd/252 SpA
-Charge Beam
-Thunderbolt
-Shadow Ball
-HP Grass
-Redone Set- Easily takes out Pert and grounds (save for Gliscor) with HP Grass. Thunderbolt for a powerful & accurate STAB, Charge Beam to raise SpA, and Shadow Ball is pretty much its only other special attacking option. Timid/Max speed EVs leaves it with a huge 394, outspeeding pretty much everything else.

Infernape @ Life Orb
Blaze
Jolly (+Spd/-SpA)
64 HP/252 Atk/192 Spd
-Fire Punch
-Close Combat
-Stone Edge
-Swords Dance
Excellent physical sweeper. Boosts its Atk with Swords Dance, then sweeps through the opponent's team. Very simple. However, it's sometimes countered by faster Infernapes with Earthquake, resulting in a OHKO.

Rotom-C @ Leftovers
Levitate
Timid (+Spd/-Atk)
252 HP/68 Def/188 Spd
-Thunderbolt
-Shadow Ball
-Will-o-Wisp
-Substitute
WoW'er/Staller. Easily sets up burns with WoW, then Substitute. Pert gets scared off by a potential Leaf Storm, and ghosts and waters are easily defeated by its attacks.
There you go.
I have noticed some weak points on my own, I've overused Electric and Ghost attacks. If gravity gets in play, then I'll get destroyed by ground attacks. A special wall is horrible to encounter if Infernape is already dead, as I don't expect Swampert to do anything super-special.
[Credit for pics to Deviantart users]