Nvm I'm gonna take Heracross-Mega
Heracross-Mega @ Heracronite
Ability: Guts
EVs: 252 Atk / 4 Def / 252 Spe
Adamant Nature
- Close Combat
- Pin Missile
- Rock Blast
- Swords Dance
These two form an incredible wallbreaking core, with Gengar taking care of the fairies and psychics that trouble Heracross while Hera takes on the steels and darks. In particular, I wanted an answer to, T-tar, Alolan Muk and Celesteela. Heracross can 2HKO the defensive variant:
252+ Atk Heracross-Mega Close Combat vs. 252 HP / 132+ Def Celesteela: 220-259 (55.2 - 65%) -- guaranteed 2HKO after Leftovers recovery
Gengar can 2HKO the offensive variant itself with Shadow Ball so it's not an issue. What separates Heracross from the other fightings is that it doesn't rely on HJK, which isn't very good to use vs Celesteela. Muk-Alolan has poor physical bulk and Ttar is 4x weak to CC, so both don't handle it well.
The moveset is self-explanatory - SD boosts its attack to pretty much unwallable levels, the dual STAB cover a good portion of the metagame and Rock Blast covers Fires and Flyings that attempt to exploit Heracross. Adamant gives it the power it needs to truly break through teams. Guts lets it function even if it gets burned without having to use SD, though Moxie could be used to gain boosts before you evolve. Both are rather situational so it doesn't matter.
Heracross-Mega is an incredibly effective breaker, and Gengar synergizes with it nearly perfectly.