Terrakion for S rank.
Terrakion @ Choice Band/Scarf
Ability:
Huge Power Justified
EVs: Max speed and attack with 4 HP
Adamant/Jolly depending on your preference
-Close Combat
-Stone Edge/Rock Slide
-Earthquake
-Poison Jab/Iron Head/X-scissor
This can tear things apart, it takes care of steel, one of rock's biggest problems, and now that aegislash is gone (on steel) he can hit anything for atleast neutral damage, scarf works as an amazing revenge killer and band works as a marvelous wallbreaker.
Terrakion @ Life Orb/Leftovers
Ability:
Pure Power Justified
EVs: Max speed and attack with 4 HP
Adamant/Jolly depending on your preference
-Close Combat
-Stone Edge/Rock Slide
-Substitute/Earthquake
-Swords Dance/Rock Polish
It can bluff a scarf set or force something out and then right after set up, and if it does, it can proceed to sweep or wallbreak better than the choiced set, although you need a turn to set up and only 2-3 attack to abuse.
Terrakion @ Focus Sash/Leftovers/Life Orb
Ability:
Prankster Justified
EVs: Max speed and attack with 4 HP
Adamant/Jolly depending on your preference
-Stealth Rock
-Taunt
-Close Combat
-Stone Edge/Rock Slide
Really fast stealth rocker boasting 108 speed, can stall break with taunt, still has 2 powerful as fuck moves powered up by stab and 129 attack stat, life orb/focus sash is the preferred item here,but leftovers is still viable, it can cripple stuff like skarmory,gliscor,klefki and mew because it has an incredibly fast taunt, and if skarmory is carrying the whirlwind + spikes + Stealth rock + roost set, its taunt bait and most people expect terrakion to be choiced, so skarmory will most likely stay in to scout the choice scarf or band.
Why does this deserve S rank? Its a great wallbreaker,revenge killer,stallbreaker and setup sweeper. Overall its pretty versatile, has really good stats,great unique typing, not only offensively but not too shabby defensively either and not a bad movepool as it can deal with its weaknesses if they are a little damaged already. And lets face it, when talonflame was around, the only chance fighting had against it was terrakion and there is a reason its ou.