Thanks so much. This is what my team is looking like now.
Heracross @ Heracronite
Ability: Swarm
EVs: 40 HP / 252 Atk / 216 Spe
Adamant Nature
- Pin Missile
- Close Combat
- Rock Blast
- Earthquake
Clefable @ Leftovers
Ability: Magic Guard
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
- Stealth Rock
- Moonblast
- Flamethrower
- Soft-Boiled
Sableye @ Leftovers
Ability: Prankster
EVs: 252 HP / 252 Def / 4 SpD
Careful Nature
- Taunt
- Will-o-Wisp
- Recover
- Knock Off
Gourgeist-Small @ Leftovers
Ability: Frisk
EVs: 252 HP / 32 Def / 224 Spe
Jolly Nature
- Substitute
- Leech Seed
- Will-O-Wisp
- Protect
Rotom-Wash @ Chesto Berry
Ability: Levitate
EVs: 248 HP / 216 SpD / 44 Spe
Calm Nature
- Volt Switch
- Hydro Pump
- Will-O-Wisp
- Rest
Mandibuzz (F) @ Leftovers
Ability: Overcoat
EVs: 248 HP / 136 Def / 108 SpD / 16 Spe
Bold Nature
- Roost
- Defog
- Whirlwind
- Foul Play
Swarm isn't useful on Heracross pre-Mega, tbh. If Guts Heracross gets statused (especially when burned), it can choose not to Mega Evolve at all and proceed to steamroll the opponent with Guts-powered attacks. With Moxie, Heracross can hold off of Mega Evolving on purpose in order to get a +1 Attack boost (recommended to do this on a weakened opponent), then Mega Evolve into a more threatening Mega. However, Heracross is one of those Pokemon that Mega Evolves ASAP.