[Pocket]

Specially Defensive:

~ After revisiting this set, the slashitis really make this set look disorganized. From reading many RMTs and personal experience from the ladder, I say that Lava Plume, Protect, and Toxic are pretty much staples, with the last slot being interchangeable among Stealth Rock, Roar, and Earth Power. Thus I suggest the move order to be changed to the following:

move 1: Lava Plume
move 2: Protect
move 3: Toxic
move 4: Stealth Rock / Earth Power / Roar
(move HP Ice and Taunt to AC)

Substitute:

~ Well written, nothing much to add other than specify Vaporeon as ones with Hydration, because Water Absorb Vaporeon would certainly be annoyed by status.

~ Actually I have a couple of things to say. Although Natural Cure Pokemon can switch out to cure status, it is still suffering from the status affliction while it's active. Thus the likes of offensive Starmie would find itself worn out after a 2-3 turns of status damage, and same can be said for Chansey / Blissey without Aromatherapy, wearing down just as fast as Heatran most likely. You should thus clarify this in your set comments. The only Pokemon truly unperturbed by this set is Hydration Vaporeon.

~ Sand and hazards would be particularly synergistic with this set, as sand exacerbates the passive damage of status afflictions, and hazards would punish Natural Cure and other hardy Pokemon from switching out.

~ AC Protect and Taunt: This Heatran can be particularly nasty in conjunction with Protect or Taunt over Earth Power, serving a similar role as toxicstalling or stallbreaker Gliscor. It can simply Toxic-stall with Sub + Protect or prevent the likes of Chansey, Blissey, etc from healing themselves or their teammates with Softboiled / Wish / Aromatherapy.

Choice Scarf:

~ Actually Fire Blast is quite indispensable on Heatran, since it has great sweep potential and much less set-up bait than post special drop from Overheat. Slash Overheat before Flamethrower as an accurate and powerful alternative to Fire Blast, when Heatran can afford the special drop but cannot afford to miss. Remove Overheat slash on Fire Blast of course.

• Make sure your Set Comments and AC reflect this change (ie more emphasis on Fire Blast and less emphasis on Overheat; explain why Overheat is NOT Tran's main move and Fire Blast is its main move.)

Although base 77 Speed is seemingly not sufficient, it still lets Heatran outrun up to base 130s, as well as +1 Adamant Dragonite.

I'd also include +1 Gyarados, since Heatran can technically check it with Hidden Power Electric.

~ Remove HP Grass from AC; it's simply an inferior move that should never be used on ScarfTran over HP Ice / HP Ele

~ AC Stealth Rock, Sleep Talk, Will-O-Wisp, Toxic: I've seen players actually use on there Scarf Heatran, because it can afford to do so. Heatran forces many switches that allows it to set up Stealth Rock early-game. With Sleep Talk, it can absorb sleep from likes of Amoonguss and Venusaur and not be useless. Will-O-Wisp and Toxic are targeted on common bulky Water, Rock, or Dragon type switch-ins that attempt to wall or set up on Heatran.

~ AC Stone Edge for no other purpose than killing Volcarona, which scores an OHKO even with Timid Nature.

~ AC Modest Nature: Heatran loses the ability to hit before +1 Adamant Dragonite and +1 Adamant Gyarados, but it does provide Heatran more notable power for late-game sweep, especially on a Sun team, which most often includes a fast Chlorophyll sweeper anyways.

Weather Trapper:

Air Balloon will also help against Dugtrio; it will not be able to trap Heatran, and will be KOed through Focus Sash if it switches on Magma Storm, effectively making this Heatran a difficult target for Dugtrio.

Include that it also aids in dispatching Hippowdon, as it is forced to either Ice Fang or better yet Whirlwind, as it cannot touch Air Balloon Heatran otherwise.

~ AC Taunt to prevent Tyranitar / Hippowdon / Blissey from setting up rocks. It also have the added bonus of preventing Hippowdon from phazing Heatran or Blissey from healing, thereby being at Heatran's full mercy (assuming tran is holding Air Balloon) while entrapped.

~ AC Modest & Life Orb to have the greatest potential to 2HKO Blissey / Chansey with Magma Storm after little residual damage.

~ AC Shuca Berry & Max HP to comfortably survive Dugtrio's EQ and retaliate KO with Magma Storm

For this reason, Dugtrio is an excellent partner. Although it seems to be redundant as it can also trap, it is able to dispose of Tyranitar, no matter which set it runs.

I think redundant trapping is actually the whole point here. Heatran initiates the trapping of weather-inducers with Magma Storm, and do as much damage as possible. Even if Heatran falls short and bites the dust, Dugtrio immediately replaces its spot and finish off the weather summoners without fail (well except for Hippowdon perhaps, which Heatran should be able to dispose on its own). It's this ability to double-whammy the summoner with a dual-trapping core without being completely useless outside of this function that makes this set so potent.

Make sure that the opponent does not have a Pokémon that can change the weather back before sacrificing this set or Ninetales. If your opponent has something like Tornadus with Rain Dance, it can undo all your hard effort.

I don't like this quote. If Heatran has contributed in the removal of the weather summoner, then it has done its job. Tornadus can change the weather, but it'll be temporary, Ninetales can change the weather. Now this is a different story, if you lose Ninetales, and Tornadus removes Sun with Rain Dance, but this is an analysis about Heatran not Ninetales... I'd simply remove this last part.