Escavalier @ Choice Band  
Ability: Overcoat  
EVs: 4 HP / 252 Atk / 252 Spe  
Jolly Nature  
- Megahorn  
- Drill Run  
- Iron Head  
- Knock Off / Poison Jab / Pursuit / Toxic

Possible Items: Choice Band, Assault Vest, Leftovers, Lum Berry
Role
Slow and bulky, but not with 120/130 speed. Works nicely with Arceus Fairy in a team. 120 speed and 135 attack with a possible choice band is scary!

Set
Max speed and attack with a jolly nature lets Escavalier reach 372 Speed, which is fast for a mon with its stats. Being reasonably bulky (70 105 105) combined with only one weakness lets escavalier live a neutral hit or two. Megahorn and iron head for stab. Drill run for Magnezone, Heatran, Muk Alola, Nidoking and Marowak Alola (and Groudon Primal to some extent) among others. Knock off for psychic and ghost mons. Poison Jab is a possibility but it doesnt really hit anything noteworthy that can't be dealth with using iron head or megahorn. Pursuit for trapping psychics or when you are certain that the opponent will switch. Toxic for bulky (semi) unbreakable mons like Alomomola.  

Calcs (Banded)
252 Atk Choice Band Escavalier Drill Run vs. 0 HP / 0 Def Groudon-Primal: 180-212 (52.7 - 62.1%) -- guaranteed 2HKO
252 Atk Choice Band Escavalier Megahorn vs. 252 HP / 4 Def Latias-Mega: 516-608 (102.3 - 120.6%) -- guaranteed OHKO
252 Atk Choice Band Escavalier Iron Head vs. 252 HP / 252+ Def Clefable: 254-302 (64.4 - 76.6%) -- guaranteed 2HKO after Leftovers recovery
252 Atk Choice Band Escavalier Knock Off (97.5 BP) vs. 248 HP / 0 Def Marowak-Alola: 302-356 (93.4 - 110.2%) -- 56.3% chance to OHKO
252 Atk Choice Band Escavalier Pursuit vs. 0 HP / 40 Def Mewtwo-Mega-Y: 340-402 (96.3 - 113.8%) -- 75% chance to OHKO (When switching out)
252 Atk Choice Band Escavalier Megahorn vs. 32 HP / 64 Def Kyogre-Primal: 307-363 (87.9 - 104%) -- guaranteed OHKO after Stealth Rock
252 Atk Choice Band Escavalier Iron Head vs. 252 HP / 4 Def Shuckle: 192-228 (38 - 45.2%) -- guaranteed 2HKO after Stealth Rock
252 Atk Choice Band Escavalier Drill Run vs. 0 HP / 0 Def Nidoking: 334-394 (110.2 - 130%) -- guaranteed OHKO

Calcs (not banded)
252 Atk Escavalier Drill Run vs. 4 HP / 0 Def Magnezone: 320-380 (113.4 - 134.7%) -- guaranteed OHKO
252 Atk Escavalier Drill Run vs. 0 HP / 4 Def Heatran: 340-404 (105.2 - 125%) -- guaranteed OHKO
252 Atk Escavalier Knock Off (97.5 BP) vs. 0 HP / 0 Def Marowak-Alola: 202-238 (77.3 - 91.1%) -- guaranteed OHKO after Stealth Rock
252 Atk Escavalier Megahorn vs. 0 HP / 0 Def Serperior: 422-498 (145 - 171.1%) -- guaranteed OHKO
252 Atk Escavalier Megahorn vs. 4 HP / 0 Def Kartana: 160-189 (61.5 - 72.6%) -- guaranteed 2HKO after Stealth Rock