Probably just Swords Dance, Photon Geyser, Earthquake, and Outrage, which is able to OHKO Mega Sableye at +2, and deal a good amount to Arceus-Dark, defensive Yveltal, and Lugia, KOing them after chip. It has a bit of trouble with the rarer Mega Slowbro and Skarmory, and can be revenge killed by Mega Gengar and Ditto. Stone Edge > Outrage can possibly lure and OHKO Ho-Oh, but gets walled by the Dark-types after it reveals Ultra.
A Calm Mind set with Photon Geyser, Dragon Pulse, and Heat Wave could be able to get around Slowbro and Skarmory, still win the 1v1 against Mega Sableye and Arceus-Dark, and possibly survive an attempt from Mega Gengar to revenge kill, but it would have issue breaking through Blissey/Chansey and Pursuit users.