Excadrill (F) @ Leftovers
Ability: Mold Breaker
EVs: 252 HP / 212 SpD / 44 Spe
Careful Nature
- Stealth Rock
- Rapid Spin
- Toxic/Iron Head/ Swords Dance
- Earthquake
As much bulk as possible on the special side with enough speed (223) to outspeed 144 Speed EV Tapu Bulu and Lando-T's and Rotom-W's with cheeky speed EV's.
Mold Breaker alllows it to set up Stealth Rock against Mega Sableye (still a bastard) and it can Toxic Mega Sableye, pressuring it a lot. Toxic also helps against Mantine and Pelipper and other bulky switchins in general, putting them on a timer so to speak. Its typing with Sp. Def invesment allows it to answer Tapu Koko quite handily which is a big threat right now. It also works as a check to Aegislash with Earthquake barring offensive Sacred Sword+ Shadow Sneak variants. Other things it matches up well against, particularly as Stealth Rock setters, are Nihilego, Alolan Marowak (can't switch into it but Exca outspeeds and OHKO's, not a safe spinblock at all), Clefable etc.
Other move options are also definitely usable. Iron Head 2HKO's Tapu Bulu unless it's like Max HP/Max Def Bold, punishes Clefable and other fairies. Swords Dance pressures slower builds especially the Aegi/Toxapex defensive core although I've found it not as good as Toxic/Iron Head and kinda situational.
Support wise Sp. Def Excadrill appreciates Electric types to account for Celesteela, Skarmory and fat Water-types and a Ghost partner like Aegislash or Sableye to block opposing Spin attempts and Fighting type moves, neither of which are too strenuous to incorporate in my opinion.