According to the calculator, the ORAS set is this:
Heracross-Mega @ Heracronite
Ability: Skill Link
EVs: 240 HP/ 136 Atk/ 132 Spe
Adamant Nature
-Substitute
-Close Combat
-Pin Missile
-Rock Blast
Here's a spread I made for SM:
Heracross-Mega @ Heracronite
Ability: Moxie
EVs: 224 HP / 136 Atk / 148 Spe
Adamant Nature
- Substitute
- Close Combat
- Pin Missile
- Rock Blast
This spread hits 223 Speed, which outruns the calculator's defensive Lando-T (that has 222 speed). The Attack is the same; it just has a little less bulk and a little more speed. The extra speed investment is very important for Substitute-ing on defensive Lando since it can't break your Sub.
I still need to determine how much HP and Attack are needed to hit certain benchmarks, but I think 223 speed should be the minimum.
Some takeaways from calcs I've done so far-
- Going from 240 HP EVs to 224 means Rotom's Volt Switch can break Hera's Sub, but the chance is very low.
- Zygarde, whether SubCoil or LO DD, can never break Hera's Sub in one hit with Thousand Arrows. Adamant CB Zygarde can always break it in one hit with Thousand Arrows.
- Unboosted Horn Leech from SD Fightinium Z Bulu has a good chance to break Hera's Sub in one hit. Unboosted Superpower, however, does like 15-20%, so if Hera eats a Superpower on the switch it can wall Bulu easily. Pin Missile does like 90% minimum.
- With either 224 HP or 240 HP, Hera always eats 2 Scalds from Scarf Keldeo after Rocks, assuming no burns. CC does 90% minimum.
- Dugtrio is hard countered unless it runs Aerial Ace (that 2HKOs Hera btw).
- PhysDef Unaware Clef basically counters Hera, which needs like 200+ Attack EVs to have a somewhat decent chance to 2HKO.
- Mega Sableye's Foul Play does 25-30% but otherwise Hera's Sub walls it easily.
- 224 HP Hera has a 94% chance to live LO Latios' Psyshock at full health.
- For all of you Baton Pass haters, Hera Subs on Scoli easily and can fire off Pin Missiles, which do 45-55% to max HP Scoli.
- It switches into Specs Ash Gren's Dark Pulse decently but everything else blows it back.
- Hera's Sub can't be broken in one hit by ScarfChomp's EQ or Rock Slide.
- Outspeeds and OHKOs Mega Mawile with CC after a little prior damage; Sucker Punch does zero.
- Rock Blast OHKOs Mantine, whose Scald cannot break Hera's Sub in one hit.
- Hera's Sub has a chance to not be broken by AV Magearna's Volt Switch.
- CC reliably 2HKOs SpDef Celesteela.
- 136+ Atk Heracross-Mega Close Combat vs. 252 HP / 252+ Def Skarmory: 151-178 (45.2 - 53.2%) -- 90.6% chance to 2HKO after Stealth Rock and Leftovers recovery; this speaks for itself.
For faster spreads, 220 Speed EVs (241 Speed) outruns SubCoil Zygarde and the mons that Zygarde speed creeps.