Hi there. I decided to write up a set for Heatran using Metal Sound after I saw it in its analysis. However, it wasn't a dedicated Metal Sound set because the set was using Taunt and barely any Speed. So, I tested it out for a while and damn was it impressive. Enjoy!
Status: COMPLETE (ready for uploading)
Heatran
[SET]
name: Metal Sound
move 1: Metal Sound
move 2: Fire Blast
move 3: Earth Power
move 4: Hidden Power Grass
item: Life Orb
nature: Timid
evs: 4 Def / 252 SpA / 252 Spe
ivs: 2 Atk / 30 SpA
[SET COMMENTS]
<p>Combine base 130 Special Attack, 120 Base Power Fire Blast, and the Special Defense-reducing Metal Sound, and Heatran makes an extremely potent threat in the OU metagame. With Metal Sound, Heatran can combat Pokemon whom it otherwise cannot, such as Blissey, Tyranitar, Latias, and bulky Water-types. Because of this, Heatran can more effectively threaten its common switch-ins, making it harder to check.</p>
<p>After taking a Metal Sound, even Pokémon who resist Fire Blast will take huge amounts of damage. Earth Power and Hidden Power Grass are used for type coverage. The former hits Tyranitar and Heatran, while the latter hits Water-types who constantly shut down Heatran. In OU, only Latias, Salamence, and Dragonite resist this combination of moves; however, if you are able to hit them with Fire Blast after a Metal Sound, they are in for a deadly surprise.</p>
[ADDITIONAL COMMENTS]
<p>To demonstrate the power Heatran's Life Orb-boosted attacks have against opponents hit by Metal Sound, below are several damage calculations against Pokemon who would otherwise threaten Heatran.</p>
<ul class="damage_calculation">
<li>Fire Blast vs 0 HP / 0 SpD Timid Latias: 67% - 79%</li>
<li>Fire Blast vs 0 HP / 0 SpD Naive Salamence: 100%</li>
<li>Fire Blast vs 0 HP / 0 SpD Jolly Dragonite: 79% - 93%</li>
<li>Fire Blast vs 24 HP / 232 SpD Calm Blissey: 46% - 54%</li>
<li>Earth Power vs 160 HP / 0 SpD Adamant Tyranitar: 89% - 100%</li>
<li>Hidden Power Grass vs 188 HP / 0 SpD Bold Vaporeon: 92% - 100%</li>
<li>Hidden Power Grass vs 252 HP / 0 SpD Bold Suicune: 87% - 100%</li>
</ul>
<p>The strategy to using this set effectively is to switch Heatran in on someone whom it can threaten instantly, such as Rotom-A or Jirachi, and use Metal Sound since your opponent will likely switch out. Once that has been accomplished, proceed to hit the switch-in with the most appropriate attack.</p>
<p>Since Heatran appreciates the use of lures to bring in Pokemon whom it can set up on, that should be taken into account when using Metal Sound Heatran. Jirachi is a great lure for Rotom-A, allowing Heatran to come in without much worry and gain a potential Flash Fire Boost from Will-O-Wisp or, in Rotom-H's case, Overheat. If you are capable of scoring a Flash Fire boost, Heatran becomes powerful enough to OHKO Latias after being hit by Metal Sound with Fire Blast. Another great teammate to use is Gengar, who can lure in Choice Scarf Jirachi and Choice Band Scizor. Entry hazard support is also strongly recommended as it helps Heatran score the needed KOes that it otherwise can't achieve, such as against Dragonite. Metal Sound also tends to force switches, racking up entry hazard damage on the opponent. Swampert makes a great Stealth Rock supporter with its overall bulk and it also lures in Grass-types, like Celebi, of whom Heatran can take advantage. Skarmory is one of the most reliable Spikes users in the OU metagame, making it a prime candidate for setting them up. It also attracts Fire-type attacks and Pokemon like Rotom-A, whom Heatran can switch into without much fear.</p>
Status: COMPLETE (ready for uploading)
Heatran
[SET]
name: Metal Sound
move 1: Metal Sound
move 2: Fire Blast
move 3: Earth Power
move 4: Hidden Power Grass
item: Life Orb
nature: Timid
evs: 4 Def / 252 SpA / 252 Spe
ivs: 2 Atk / 30 SpA
[SET COMMENTS]
<p>Combine base 130 Special Attack, 120 Base Power Fire Blast, and the Special Defense-reducing Metal Sound, and Heatran makes an extremely potent threat in the OU metagame. With Metal Sound, Heatran can combat Pokemon whom it otherwise cannot, such as Blissey, Tyranitar, Latias, and bulky Water-types. Because of this, Heatran can more effectively threaten its common switch-ins, making it harder to check.</p>
<p>After taking a Metal Sound, even Pokémon who resist Fire Blast will take huge amounts of damage. Earth Power and Hidden Power Grass are used for type coverage. The former hits Tyranitar and Heatran, while the latter hits Water-types who constantly shut down Heatran. In OU, only Latias, Salamence, and Dragonite resist this combination of moves; however, if you are able to hit them with Fire Blast after a Metal Sound, they are in for a deadly surprise.</p>
[ADDITIONAL COMMENTS]
<p>To demonstrate the power Heatran's Life Orb-boosted attacks have against opponents hit by Metal Sound, below are several damage calculations against Pokemon who would otherwise threaten Heatran.</p>
<ul class="damage_calculation">
<li>Fire Blast vs 0 HP / 0 SpD Timid Latias: 67% - 79%</li>
<li>Fire Blast vs 0 HP / 0 SpD Naive Salamence: 100%</li>
<li>Fire Blast vs 0 HP / 0 SpD Jolly Dragonite: 79% - 93%</li>
<li>Fire Blast vs 24 HP / 232 SpD Calm Blissey: 46% - 54%</li>
<li>Earth Power vs 160 HP / 0 SpD Adamant Tyranitar: 89% - 100%</li>
<li>Hidden Power Grass vs 188 HP / 0 SpD Bold Vaporeon: 92% - 100%</li>
<li>Hidden Power Grass vs 252 HP / 0 SpD Bold Suicune: 87% - 100%</li>
</ul>
<p>The strategy to using this set effectively is to switch Heatran in on someone whom it can threaten instantly, such as Rotom-A or Jirachi, and use Metal Sound since your opponent will likely switch out. Once that has been accomplished, proceed to hit the switch-in with the most appropriate attack.</p>
<p>Since Heatran appreciates the use of lures to bring in Pokemon whom it can set up on, that should be taken into account when using Metal Sound Heatran. Jirachi is a great lure for Rotom-A, allowing Heatran to come in without much worry and gain a potential Flash Fire Boost from Will-O-Wisp or, in Rotom-H's case, Overheat. If you are capable of scoring a Flash Fire boost, Heatran becomes powerful enough to OHKO Latias after being hit by Metal Sound with Fire Blast. Another great teammate to use is Gengar, who can lure in Choice Scarf Jirachi and Choice Band Scizor. Entry hazard support is also strongly recommended as it helps Heatran score the needed KOes that it otherwise can't achieve, such as against Dragonite. Metal Sound also tends to force switches, racking up entry hazard damage on the opponent. Swampert makes a great Stealth Rock supporter with its overall bulk and it also lures in Grass-types, like Celebi, of whom Heatran can take advantage. Skarmory is one of the most reliable Spikes users in the OU metagame, making it a prime candidate for setting them up. It also attracts Fire-type attacks and Pokemon like Rotom-A, whom Heatran can switch into without much fear.</p>