I would go for Fire Spin / Overheat, though Air Slash / Overheat can serve you well if you don't have enough good attackers for Machamp raids. I'm still looking for a 100% one, but have many of them (as it's my favorite Pokémon xD) with slightly different movesets :)
In any case, its current role is as a bug / grass slayer, but in the near future would also help with steel mons that have ground coverage (like Metagross). Enjoy your 100%! :p