Set details (Moveset choice, EVs, Team Options)
Heracross @ Heracronite
Ability: Guts
EVs: 248 HP / 84 Atk / 76 Def / 100 Spe
Adamant Nature
- Pin Missile/Swords Dance
- Substitute/Swords Dance/Bullet Seed
- Rock Blast
- Close Combat
Moveset choice: Rock Blast and Close Combat are basically mandatory for neutral coverage, and both hit hard due to Skill Link and STAB, respectively. Your other 2 slots have a variety of options. I personally choose Pin Missile because it lets you eat bulky Psychics alive and 2HKO's anything that doesn't resist it (TankChomp is cleanly 2HKO'd) while avoiding recoil damage (making TankChomp very sad). Substitute lets you have a much easier time predicting (as you'll see in the replays) and your sub is actually fairly bulky (unboosted CroCune Scalds don't break it, Double Dance Lando-T that use Rock Slide can't break it without a boost, CM Manaphy has a 50% chance to break it, Rotom-W Volt Switch doesn't break it, TankChomp Dragon Tail doesn't break it, unboosted LO Bisharp Sucker Punch doesn't break it, Defensive Lando-T doesn't have even a 50% chance to break your Sub with Stone Edge, Defensive Hippo has to Whirlwind it out, and so on). Swords Dance lets you murder many many things but you're not very fast with this set (which is a tank designed to eat up hits and hit back hard) and things like Hippo and Skarm still wall you (and the regular Smogon spread). Bullet Seed lets you destroy Quagsire (which dies to 2 unboosted Pin Missiles), Azumarill (this is nice since you outspeed), Swampert, Alomomola, and other bulky waters. If your team has trouble with those, Bullet Seed is a good option.
EVs: You might be wondering why this spread is better than the standard Smogon spread (Jolly, max Speed/Attack). Credit to ben gay from the Creative and Underrated Sets thread, where he talked about how CBB came up with a bulky Mega Heracross set and how good it was. Running Max Speed isn't really great on Mega Heracross, since you still get outsped and forced out by things like Offensive Magma Storm Heatran, the Lati twins, strong Psyshock users, Keldeo, and so on. Plus, you're not utilizing your great bulk to it's fullest, so you can't even switch in on ScarfTar consistently since Stone Edge is a 2HKO. Since you have 0 recovery and are not likely to have a WishPasser (not counting Healing Wish), you get chipped down so easily that you'll get revenge killed pretty soon. Thus, I went for the mostly-bulk route. I like to tweak EVs so I spent some time doing and testing that (ben gay/CBB spread) and came up with this.
The 100 speed EVs are for outspeeding 8 Speed Rotom-W post-Mega so you can Sub on them and avoid being Wisp'd. They also let you out-slow Defensive Landorus-T so you take little from U-Turn and hit something hard on the switch/go for the sub. If you don't care about the speed as much, run 8 Speed EVs to outspeed Rotom-W pre-Mega and dump the rest in bulk (Def/SpDef is your call, although most of the attacks you'll be sponging are physical attacks, so I'd dump them in Defense since you already avoid important 2HKOs/OHKOs on the special side with this spread.
Adamant Nature and 84 Attack EVs lets you hit 469 attack, which is the same as the Smogon Jolly and 252 Attack EVs spread, i.e. monstrously powerful.
Max HP is good because Mega Heracross actually is pretty damn beefy (80/115/105) and has a useful defensive typing that resists important things like Dark, Fighting, and Ground. Chucking the remaining EVs into defense lets you hit some very nice defensive benchmarks too. A LOT of things that can normally 2HKO or OHKO are now unable to do so and you can OHKO them back in many cases. The list below isn't comprehensive but should give you a good idea. Smogon derped and I lost the details I listed besides each calc so I'm not gonna redo them for a while because that took time, but this should give you a good idea of the bulk this has.
Noticeable things: LO Latios Psyshock doesn't OHKO you, Adamant Max Attack Play Rough doesn't OHKO you, you can beat LO Serperior in the 1v1 50% of the time, ScarfTar Crunch is set-up, you counter Mega Lopunny and most Mega Scizor, etc.
252+ Atk Huge Power Azumarill Play Rough vs. 248 HP / 76 Def Mega Heracross: 296-350 (81.5 - 96.4%) -- guaranteed 2HKO
+6 252+ Atk Huge Power Azumarill Aqua Jet vs. 248 HP / 76 Def Mega Heracross: 262-310 (72.1 - 85.3%) -- guaranteed 2HKO
252+ Atk Life Orb Excadrill Iron Head vs. 248 HP / 76 Def Mega Heracross: 160-188 (44 - 51.7%) -- 14.1% chance to 2HKO
252+ Atk Life Orb Excadrill Earthquake vs. 248 HP / 76 Def Mega Heracross: 99-117 (27.2 - 32.2%) -- guaranteed 4HKO
+2 252+ Atk Life Orb Excadrill Iron Head vs. 248 HP / 76 Def Mega Heracross: 317-374 (87.3 - 103%) -- 25% chance to OHKO
252 SpA Life Orb Latios Psyshock vs. 248 HP / 76 Def Mega Heracross: 283-335 (77.9 - 92.2%) -- guaranteed 2HKO
252+ Atk Choice Band Dragonite Outrage vs. 248 HP / 76 Def Mega Heracross: 273-322 (75.2 - 88.7%) -- guaranteed 2HKO
252 SpA Choice Specs Keldeo Hydro Pump vs. 248 HP / 0 SpD Mega Heracross: 256-303 (70.5 - 83.4%) -- guaranteed 2HKO
252 SpA Choice Specs Keldeo Secret Sword vs. 248 HP / 76 Def Mega Heracross: 86-102 (23.6 - 28%) -- 89% chance to 4HKO
252 Atk Tyranitar Stone Edge vs. 248 HP / 76 Def Mega Heracross: 139-165 (38.2 - 45.4%) -- guaranteed 3HKO after sandstorm damage
252 Atk Tyranitar Crunch vs. 248 HP / 76 Def Mega Heracross: 55-66 (15.1 - 18.1%) -- guaranteed 5HKO after sandstorm damage
252+ Atk Choice Band Tyranitar Crunch vs. 248 HP / 76 Def Mega Heracross: 91-108 (25 - 29.7%) -- 0.5% chance to 3HKO after sandstorm damage
+2 252 Atk Life Orb Bisharp Iron Head vs. 248 HP / 76 Def Mega Heracross: 274-324 (75.4 - 89.2%) -- guaranteed 2HKO
+2 252 Atk Life Orb Bisharp Sucker Punch vs. 248 HP / 76 Def Mega Heracross: 136-161 (37.4 - 44.3%) -- guaranteed 3HKO
0- SpA Garchomp Fire Blast vs. 248 HP / 0 SpD Mega Heracross: 114-136 (31.4 - 37.4%) -- 83.7% chance to 3HKO
0 Atk Garchomp Earthquake vs. 248 HP / 76 Def Mega Heracross: 56-66 (15.4 - 18.1%) -- possible 6HKO
252 SpA Life Orb Alakazam Psyshock vs. 248 HP / 76 Def Mega Heracross: 291-346 (80.1 - 95.3%) -- guaranteed 2HKO
252 SpA Heatran Magma Storm vs. 248 HP / 0 SpD Mega Heracross: 314-372 (86.5 - 102.4%) -- 12.5% chance to OHKO
+2 252 Atk Technician Breloom Bullet Seed (3 hits) vs. 248 HP / 76 Def Mega Heracross: 153-180 (42.1 - 49.5%) -- guaranteed 3HKO
+2 252 Atk Technician Breloom Rock Tomb vs. 248 HP / 76 Def Mega Heracross: 163-192 (44.9 - 52.8%) -- 25.8% chance to 2HKO
252 SpA Life Orb Serperior Leaf Storm vs. 248 HP / 0 SpD Mega Heracross: 92-109 (25.3 - 30%) -- guaranteed 4HKO
+2 252 SpA Life Orb Serperior Hidden Power Fire vs. 248 HP / 0 SpD Mega Heracross: 229-270 (63 - 74.3%) -- guaranteed 2HKO
252+ SpA Choice Specs Hoopa Unbound Dark Pulse vs. 248 HP / 0 SpD Mega Heracross: 126-149 (34.7 - 41%) -- guaranteed 3HKO
160 Atk Life Orb Hoopa Unbound Gunk Shot vs. 248 HP / 76 Def Mega Heracross: 156-185 (42.9 - 50.9%) -- 3.9% chance to 2HKO
252 SpA Mega Manectric Overheat vs. 248 HP / 0 SpD Mega Heracross: 280-330 (77.1 - 90.9%) -- guaranteed 2HKO
252 SpA Mega Manectric Thunderbolt vs. 248 HP / 0 SpD Mega Heracross: 145-172 (39.9 - 47.3%) -- guaranteed 3HKO
252 Atk Mega Lopunny Return vs. 248 HP / 76 Def Mega Heracross: 144-169 (39.6 - 46.5%) -- guaranteed 3HKO
252 Atk Mega Lopunny High Jump Kick vs. 248 HP / 76 Def Mega Heracross: 91-108 (25 - 29.7%) -- guaranteed 4HKO
+1 252 Atk Mega Lopunny Return vs. 248 HP / 76 Def Mega Heracross: 214-253 (58.9 - 69.6%) -- guaranteed 2HKO
252 Atk Landorus-T Stone Edge vs. 248 HP / 76 Def Mega Heracross: 98-116 (26.9 - 31.9%) -- guaranteed 4HKO
252 Atk Landorus-T Earthquake vs. 248 HP / 76 Def Mega Heracross: 73-87 (20.1 - 23.9%) -- guaranteed 5HKO
+2 252 Atk Landorus-T Stone Edge vs. 248 HP / 76 Def Mega Heracross: 196-231 (53.9 - 63.6%) -- guaranteed 2HKO
+2 252 Atk Landorus-T Earthquake vs. 248 HP / 76 Def Mega Heracross: 147-173 (40.4 - 47.6%) -- guaranteed 3HKO
252+ Atk Technician Mega Scizor Bullet Punch vs. 248 HP / 76 Def Mega Heracross: 100-118 (27.5 - 32.5%) -- guaranteed 4HKO
+2 252+ Atk Technician Mega Scizor Bullet Punch vs. 248 HP / 76 Def Mega Heracross: 198-234 (54.5 - 64.4%) -- guaranteed 2HKO
+2 84 Atk Technician Mega Scizor Bullet Punch vs. 248 HP / 76 Def Mega Heracross: 162-192 (44.6 - 52.8%) -- 24.6% chance to 2HKO
252 SpA Magnezone Thunderbolt vs. 248 HP / 0 SpD Mega Heracross: 142-168 (39.1 - 46.2%) -- guaranteed 3HKO
0 SpA Mega Latias Ice Beam vs. 248 HP / 0 SpD Mega Heracross: 84-99 (23.1 - 27.2%) -- 64.3% chance to 4HKO
+1 0 SpA Mega Latias Ice Beam vs. 248 HP / 0 SpD Mega Heracross: 124-147 (34.1 - 40.4%) -- guaranteed 3HKO
0 SpA Mega Latias Dragon Pulse vs. 248 HP / 0 SpD Mega Heracross: 118-139 (32.5 - 38.2%) -- 96.7% chance to 3HKO
+6 252+ Atk Huge Power Azumarill Aqua Jet vs. 248 HP / 76 Def Mega Heracross: 262-310 (72.1 - 85.3%) -- guaranteed 2HKO
252+ Atk Life Orb Excadrill Iron Head vs. 248 HP / 76 Def Mega Heracross: 160-188 (44 - 51.7%) -- 14.1% chance to 2HKO
252+ Atk Life Orb Excadrill Earthquake vs. 248 HP / 76 Def Mega Heracross: 99-117 (27.2 - 32.2%) -- guaranteed 4HKO
+2 252+ Atk Life Orb Excadrill Iron Head vs. 248 HP / 76 Def Mega Heracross: 317-374 (87.3 - 103%) -- 25% chance to OHKO
252 SpA Life Orb Latios Psyshock vs. 248 HP / 76 Def Mega Heracross: 283-335 (77.9 - 92.2%) -- guaranteed 2HKO
252+ Atk Choice Band Dragonite Outrage vs. 248 HP / 76 Def Mega Heracross: 273-322 (75.2 - 88.7%) -- guaranteed 2HKO
252 SpA Choice Specs Keldeo Hydro Pump vs. 248 HP / 0 SpD Mega Heracross: 256-303 (70.5 - 83.4%) -- guaranteed 2HKO
252 SpA Choice Specs Keldeo Secret Sword vs. 248 HP / 76 Def Mega Heracross: 86-102 (23.6 - 28%) -- 89% chance to 4HKO
252 Atk Tyranitar Stone Edge vs. 248 HP / 76 Def Mega Heracross: 139-165 (38.2 - 45.4%) -- guaranteed 3HKO after sandstorm damage
252 Atk Tyranitar Crunch vs. 248 HP / 76 Def Mega Heracross: 55-66 (15.1 - 18.1%) -- guaranteed 5HKO after sandstorm damage
252+ Atk Choice Band Tyranitar Crunch vs. 248 HP / 76 Def Mega Heracross: 91-108 (25 - 29.7%) -- 0.5% chance to 3HKO after sandstorm damage
+2 252 Atk Life Orb Bisharp Iron Head vs. 248 HP / 76 Def Mega Heracross: 274-324 (75.4 - 89.2%) -- guaranteed 2HKO
+2 252 Atk Life Orb Bisharp Sucker Punch vs. 248 HP / 76 Def Mega Heracross: 136-161 (37.4 - 44.3%) -- guaranteed 3HKO
0- SpA Garchomp Fire Blast vs. 248 HP / 0 SpD Mega Heracross: 114-136 (31.4 - 37.4%) -- 83.7% chance to 3HKO
0 Atk Garchomp Earthquake vs. 248 HP / 76 Def Mega Heracross: 56-66 (15.4 - 18.1%) -- possible 6HKO
252 SpA Life Orb Alakazam Psyshock vs. 248 HP / 76 Def Mega Heracross: 291-346 (80.1 - 95.3%) -- guaranteed 2HKO
252 SpA Heatran Magma Storm vs. 248 HP / 0 SpD Mega Heracross: 314-372 (86.5 - 102.4%) -- 12.5% chance to OHKO
+2 252 Atk Technician Breloom Bullet Seed (3 hits) vs. 248 HP / 76 Def Mega Heracross: 153-180 (42.1 - 49.5%) -- guaranteed 3HKO
+2 252 Atk Technician Breloom Rock Tomb vs. 248 HP / 76 Def Mega Heracross: 163-192 (44.9 - 52.8%) -- 25.8% chance to 2HKO
252 SpA Life Orb Serperior Leaf Storm vs. 248 HP / 0 SpD Mega Heracross: 92-109 (25.3 - 30%) -- guaranteed 4HKO
+2 252 SpA Life Orb Serperior Hidden Power Fire vs. 248 HP / 0 SpD Mega Heracross: 229-270 (63 - 74.3%) -- guaranteed 2HKO
252+ SpA Choice Specs Hoopa Unbound Dark Pulse vs. 248 HP / 0 SpD Mega Heracross: 126-149 (34.7 - 41%) -- guaranteed 3HKO
160 Atk Life Orb Hoopa Unbound Gunk Shot vs. 248 HP / 76 Def Mega Heracross: 156-185 (42.9 - 50.9%) -- 3.9% chance to 2HKO
252 SpA Mega Manectric Overheat vs. 248 HP / 0 SpD Mega Heracross: 280-330 (77.1 - 90.9%) -- guaranteed 2HKO
252 SpA Mega Manectric Thunderbolt vs. 248 HP / 0 SpD Mega Heracross: 145-172 (39.9 - 47.3%) -- guaranteed 3HKO
252 Atk Mega Lopunny Return vs. 248 HP / 76 Def Mega Heracross: 144-169 (39.6 - 46.5%) -- guaranteed 3HKO
252 Atk Mega Lopunny High Jump Kick vs. 248 HP / 76 Def Mega Heracross: 91-108 (25 - 29.7%) -- guaranteed 4HKO
+1 252 Atk Mega Lopunny Return vs. 248 HP / 76 Def Mega Heracross: 214-253 (58.9 - 69.6%) -- guaranteed 2HKO
252 Atk Landorus-T Stone Edge vs. 248 HP / 76 Def Mega Heracross: 98-116 (26.9 - 31.9%) -- guaranteed 4HKO
252 Atk Landorus-T Earthquake vs. 248 HP / 76 Def Mega Heracross: 73-87 (20.1 - 23.9%) -- guaranteed 5HKO
+2 252 Atk Landorus-T Stone Edge vs. 248 HP / 76 Def Mega Heracross: 196-231 (53.9 - 63.6%) -- guaranteed 2HKO
+2 252 Atk Landorus-T Earthquake vs. 248 HP / 76 Def Mega Heracross: 147-173 (40.4 - 47.6%) -- guaranteed 3HKO
252+ Atk Technician Mega Scizor Bullet Punch vs. 248 HP / 76 Def Mega Heracross: 100-118 (27.5 - 32.5%) -- guaranteed 4HKO
+2 252+ Atk Technician Mega Scizor Bullet Punch vs. 248 HP / 76 Def Mega Heracross: 198-234 (54.5 - 64.4%) -- guaranteed 2HKO
+2 84 Atk Technician Mega Scizor Bullet Punch vs. 248 HP / 76 Def Mega Heracross: 162-192 (44.6 - 52.8%) -- 24.6% chance to 2HKO
252 SpA Magnezone Thunderbolt vs. 248 HP / 0 SpD Mega Heracross: 142-168 (39.1 - 46.2%) -- guaranteed 3HKO
0 SpA Mega Latias Ice Beam vs. 248 HP / 0 SpD Mega Heracross: 84-99 (23.1 - 27.2%) -- 64.3% chance to 4HKO
+1 0 SpA Mega Latias Ice Beam vs. 248 HP / 0 SpD Mega Heracross: 124-147 (34.1 - 40.4%) -- guaranteed 3HKO
0 SpA Mega Latias Dragon Pulse vs. 248 HP / 0 SpD Mega Heracross: 118-139 (32.5 - 38.2%) -- 96.7% chance to 3HKO
Heracross @ Heracronite
Ability: Guts
EVs: 248 HP / 252 Atk / 8 Spe
Adamant Nature
- Pin Missile/Swords Dance/Bullet Seed
- Substitute/Swords Dance
- Rock Blast
- Close Combat
You lose the ability to outspeed 0 speed Rotom-W post-mega, and lose bulk compared to my set, but in return you get more attack. Still don't have above a 33% chance to 2HKO Max Def Skarm, and a 14% to 2HKO Mixed Hippo, but it's still a noticeable power increase, as you are able to 2HKO Standard Clefable with unboosted Rock Blast which my set can't do most of the time (12% chance or thereabouts from full).
Heracross @ Heracronite
Ability: Guts
EVs: 252 Atk / 252 Spe / 4 HP
Jolly Nature
- Swords Dance/Pin Missile/Bullet Seed
- Substitute/Swords Dance
- Rock Blast
- Close Combat
Standard spread from Smogon.
Ability: Guts
EVs: 248 HP / 252 Atk / 8 Spe
Adamant Nature
- Pin Missile/Swords Dance/Bullet Seed
- Substitute/Swords Dance
- Rock Blast
- Close Combat
You lose the ability to outspeed 0 speed Rotom-W post-mega, and lose bulk compared to my set, but in return you get more attack. Still don't have above a 33% chance to 2HKO Max Def Skarm, and a 14% to 2HKO Mixed Hippo, but it's still a noticeable power increase, as you are able to 2HKO Standard Clefable with unboosted Rock Blast which my set can't do most of the time (12% chance or thereabouts from full).
Heracross @ Heracronite
Ability: Guts
EVs: 252 Atk / 252 Spe / 4 HP
Jolly Nature
- Swords Dance/Pin Missile/Bullet Seed
- Substitute/Swords Dance
- Rock Blast
- Close Combat
Standard spread from Smogon.
Team Building Process
Smogon deleted most of it, but basically, you want pivots to get into Mega Heracross in safely (Lando-T, Rotom-W), Fire/Flying/Fairy/Psychic resists (Heatran is one of the best), and ideally a Cleric or even a Wishpasser (Alomomola, Chansey, Clefable, Mew).
This is a fairly experimental team, and I've done variants with Chansey as a WishPasser to keep Mega Hera Healthy, and other crazy things.
SpDef Skarmory is there to Defog and beat Mega Diance/Clefable/Gardevoir, as well as Whirlwinding out any big threats. Shed Shell is a great item, but not mandatory in lower ladder games since Gastrodon walls Magnezone and can use it as set-up fodder.
SpDef Heatran with some speed and Taunt/Toxic/Protect is great against things like Clefable/Ferrothorn/Skarm/Chansey/Alomomola, as well as checking the Lati twins and other strong special attackers as well. The combination of Taunt/Toxic/Protect really lets you annoy/beat hazard setters and special set-up sweepers, since very few people expect the Protect (this is amazing against Mega Lopunny and Medicham too, and often nets you a free 50% on them).
Rocky Helmet Phys-Def Lando-T is pretty obvious. Gives you a nice blanket physical check, especially against Bird-Spam, Intimidate is great since most mons on this team are SpDef invested, sets Rocks, Ground immunity is great for Heatran, Electric immunity is great for Skarm (yes, HP Ice wrecks, but it buys time for Gastro or Mew to come in), and Rocky Helmet punishes Scarf Lando, Mega Lopunny, and common physical threats. Best of all though is the slow U-Turn you get, which is super important in letting you bring in Mega Heracross, which you really don't want to hard switch in.
Curse Gastrodon gives several things: a counter to Special Kyurem-B, a Water immunity (sans Mega Gyarados who is handled by Mega Heracross easily anyways), a counter to Mega Manectric and Magnezone who can run over much of this team, and a win-condition. Never fails to perform, and in conjunction with Mew, also handles all Keldeo and eases prediction. Don't be afraid to start setting up with this early, since you can still spam Scald if you want and just fish for burns on things like Ferro/Mega Venusaur and then switch out.
Finally, SpDef Mew gives a backup check to powerful Special Attackers like Mega Gardevoir, Serperior, Keldeo, Thundurus, Lati twins, and so on. It can still check Mega Medicham, and having Wisp means that strong physical attackers generally don't want to switch into it either. Having Heal Bell is super nice, since nothing on this team likes being status'd, and Gastro/Heracross being Toxic'd or even burned can completely destroy their usefulness.
Big weaknesses are there of course: Both Mega Zards *can* run through this team if their checks are weakened (Heatran/Lando-T/Mew, generally), and Mega Medicham also can bust this team open if Mew is weakened at all (since this is SpDef Mew, although PhysDef Mew is great on this team too and handles Mega Medicham with ease). TG Manaphy destroys this team, and while I'm often able to play around it with Heatran's Toxic/Protect and Gastrodon, there's no way it works as well against better players (above 1500 or so) to the point where I don't lose anything. Kyurem-Black is also a problem, and Specs Hoopa-Unbound can demolish this team as well, but the latter is true for any balance squad...or team in general to be honest, Hoopa-Unbound is a monster.
Still, this team is fun to play, so give it a shot if you want!
Heracross @ Heracronite
Ability: Guts
EVs: 248 HP / 84 Atk / 76 Def / 100 Spe
Adamant Nature
- Pin Missile
- Substitute
- Rock Blast
- Close Combat
Skarmory @ Leftovers
Ability: Sturdy
EVs: 248 HP / 236 SpD / 24 Spe
Careful Nature
- Whirlwind
- Defog
- Roost
- Iron Head
Heatran @ Leftovers
Ability: Flash Fire
EVs: 248 HP / 192 SpD / 68 Spe
Calm Nature
- Lava Plume
- Protect
- Taunt
- Toxic
Landorus-Therian @ Rocky Helmet
Ability: Intimidate
EVs: 252 HP / 232 Def / 24 SpD
Relaxed Nature
- U-turn
- Stone Edge
- Earthquake
- Stealth Rock
Gastrodon @ Leftovers
Ability: Storm Drain
EVs: 252 HP / 112 Def / 144 SpD
Sassy Nature
- Scald
- Curse
- Recover
- Earthquake
Mew @ Leftovers
Ability: Synchronize
EVs: 252 HP / 224 SpD / 32 Spe
Calm Nature
IVs: 0 Atk
- Will-O-Wisp
- Soft-Boiled
- Psychic
- Heal Bell
SpDef Skarmory is there to Defog and beat Mega Diance/Clefable/Gardevoir, as well as Whirlwinding out any big threats. Shed Shell is a great item, but not mandatory in lower ladder games since Gastrodon walls Magnezone and can use it as set-up fodder.
SpDef Heatran with some speed and Taunt/Toxic/Protect is great against things like Clefable/Ferrothorn/Skarm/Chansey/Alomomola, as well as checking the Lati twins and other strong special attackers as well. The combination of Taunt/Toxic/Protect really lets you annoy/beat hazard setters and special set-up sweepers, since very few people expect the Protect (this is amazing against Mega Lopunny and Medicham too, and often nets you a free 50% on them).
Rocky Helmet Phys-Def Lando-T is pretty obvious. Gives you a nice blanket physical check, especially against Bird-Spam, Intimidate is great since most mons on this team are SpDef invested, sets Rocks, Ground immunity is great for Heatran, Electric immunity is great for Skarm (yes, HP Ice wrecks, but it buys time for Gastro or Mew to come in), and Rocky Helmet punishes Scarf Lando, Mega Lopunny, and common physical threats. Best of all though is the slow U-Turn you get, which is super important in letting you bring in Mega Heracross, which you really don't want to hard switch in.
Curse Gastrodon gives several things: a counter to Special Kyurem-B, a Water immunity (sans Mega Gyarados who is handled by Mega Heracross easily anyways), a counter to Mega Manectric and Magnezone who can run over much of this team, and a win-condition. Never fails to perform, and in conjunction with Mew, also handles all Keldeo and eases prediction. Don't be afraid to start setting up with this early, since you can still spam Scald if you want and just fish for burns on things like Ferro/Mega Venusaur and then switch out.
Finally, SpDef Mew gives a backup check to powerful Special Attackers like Mega Gardevoir, Serperior, Keldeo, Thundurus, Lati twins, and so on. It can still check Mega Medicham, and having Wisp means that strong physical attackers generally don't want to switch into it either. Having Heal Bell is super nice, since nothing on this team likes being status'd, and Gastro/Heracross being Toxic'd or even burned can completely destroy their usefulness.
Big weaknesses are there of course: Both Mega Zards *can* run through this team if their checks are weakened (Heatran/Lando-T/Mew, generally), and Mega Medicham also can bust this team open if Mew is weakened at all (since this is SpDef Mew, although PhysDef Mew is great on this team too and handles Mega Medicham with ease). TG Manaphy destroys this team, and while I'm often able to play around it with Heatran's Toxic/Protect and Gastrodon, there's no way it works as well against better players (above 1500 or so) to the point where I don't lose anything. Kyurem-Black is also a problem, and Specs Hoopa-Unbound can demolish this team as well, but the latter is true for any balance squad...or team in general to be honest, Hoopa-Unbound is a monster.
Still, this team is fun to play, so give it a shot if you want!
Heracross @ Heracronite
Ability: Guts
EVs: 248 HP / 84 Atk / 76 Def / 100 Spe
Adamant Nature
- Pin Missile
- Substitute
- Rock Blast
- Close Combat
Skarmory @ Leftovers
Ability: Sturdy
EVs: 248 HP / 236 SpD / 24 Spe
Careful Nature
- Whirlwind
- Defog
- Roost
- Iron Head
Heatran @ Leftovers
Ability: Flash Fire
EVs: 248 HP / 192 SpD / 68 Spe
Calm Nature
- Lava Plume
- Protect
- Taunt
- Toxic
Landorus-Therian @ Rocky Helmet
Ability: Intimidate
EVs: 252 HP / 232 Def / 24 SpD
Relaxed Nature
- U-turn
- Stone Edge
- Earthquake
- Stealth Rock
Gastrodon @ Leftovers
Ability: Storm Drain
EVs: 252 HP / 112 Def / 144 SpD
Sassy Nature
- Scald
- Curse
- Recover
- Earthquake
Mew @ Leftovers
Ability: Synchronize
EVs: 252 HP / 224 SpD / 32 Spe
Calm Nature
IVs: 0 Atk
- Will-O-Wisp
- Soft-Boiled
- Psychic
- Heal Bell
One thing to note in the following replays is that Heracross's nature is wrong: I didn't edit properly so I had a Serious (neutral) nature as opposed to Adamant, which hurts my damage output quite a bit. Didn't matter in the games, but something to still note.
http://replay.pokemonshowdown.com/ou-346365965
Here, Mega Heracross is able to switch in to a Banded Azumarill Knock Off and take little, Sub up, and get some nice damage on Double Dance Landorus-T. Landorus-T later isn't able to break the sub with Rock Slide (unboosted of course), which lets me 2HKO it Rock Blast, showing the value of that added bulk of the set I use.
http://replay.pokemonshowdown.com/ou-346752009
I use Mega Heracross like an idiot here because I forget Fighting resists Bug, but I eat up a Specs Hydro Pump from Keldeo after my sub goes down and live, showcasing how nice that extra bulk is in so many situations. Plus, having Sub means that I was able to take out Talonflame as I did, and that easing of prediction is really nice given that you can often live another attack even with your Sub broken and inflict massive damage with another attack.
http://replay.pokemonshowdown.com/ou-346365965
Here, Mega Heracross is able to switch in to a Banded Azumarill Knock Off and take little, Sub up, and get some nice damage on Double Dance Landorus-T. Landorus-T later isn't able to break the sub with Rock Slide (unboosted of course), which lets me 2HKO it Rock Blast, showing the value of that added bulk of the set I use.
http://replay.pokemonshowdown.com/ou-346752009
I use Mega Heracross like an idiot here because I forget Fighting resists Bug, but I eat up a Specs Hydro Pump from Keldeo after my sub goes down and live, showcasing how nice that extra bulk is in so many situations. Plus, having Sub means that I was able to take out Talonflame as I did, and that easing of prediction is really nice given that you can often live another attack even with your Sub broken and inflict massive damage with another attack.
Conclusion on Mega Heracross's place in the current ORAS OU Meta
Mixed. On one hand, the increased prevalence of Sand Offense/Balance is great for Mega Heracross, as it eats almost all Bisharp and Tyranitar variants up with ease, and Lando-T/Garchomp really don't like Mega Heracross either since it doesn't take recoil damage and takes little from unboosted moves. The rise of Mega Latias is also great for Mega Heracross since it threatens the OHKO with Pin Missile and takes little from anything that's not Psyshock (or Draco, but Draco does below 60% and forces Mega Latias out most of the time). The rise of Landorus-T is also quite nice because Scarfed/Defensive Variants can't really hurt you much since they rely on Stone Edge to break your Sub (in Scarf's case), and Double Dance variants need to run Stone Edge or else they can't 2HKO you while you 2HKO back with Rock Blast.
Not all is well for Mega Heracross in the meta. The rise of Tornadus-Therian is very un-fun, since it while it gets 2HKO'd by any of your moves (even the AV set), Hurricane destroys you and unless you've got 0 other plays, you don't want to stay in. Hoopa Unbound also spells trouble for Mega Heracross, since while it can't switch in on anything at all, its Psychic STAB destroys you no matter what and forces you out, and it outspeeds you. Both Charizard forms, Mega Medicham, Mega Altaria, and Clefable, also all beat Mega Heracross or check it in the 1v1, and while some of these are less common, they're still as a group very, very common and pose massive threats to Mega Heracross, since several of these can also set up on Mega Heracross and threaten to sweep.
But, even though Mega Heracross has its issues, its massive power and very respectable bulk make it an incredibly dangerous wallbreaker that will decimate unprepared teams, and even prepared ones if you use Substitute at the right times and have a slow U-Turn to bring this beast in. I definitely didn't expect it to do well as it did, and while bringing it can be tough, it's worth it when you fire off an attack and watch the incoming switch in get decimated.