Escavalier

Escavalier shares similar typings and roles with other Bug-types, and it's among the handful of Bugs that have additional Steel-type resistances. While its typing and diverse moveset might be valuable for PvP, its unimpressive ATK stat and moveset for raids and gyms leaves it mostly a Dex entry outside of Trainer Battles. It's not the most amazing Pokemon for gym defense either, partly due to its lack of stats. 

Best PvE Offensive Moveset

• Bug Bite is the superior pick on offense, and gets STAB.
• Counter is actually quite a strong move, but lacks synergy for Escavalier's role.
• Megahorn is Escavalier's best charge move, and fulfills its Bug-type role.
• Drill Run is okay, but lacks STAB and would be better used by Ground-type Pokemon.
• Aerial Ace is pretty bad.
• Acid Spray is entirely a PvP move. 

Best PvE Defensive Moveset

• Counter hits a lot harder on defense, and provides decent coverage.
• Bug Bite gets STAB, but its base power is a lot lower. 
• Aerial Ace as a 3-bar move can be used most frequently. 
• Drill Run provides coverage against Escavalier's only weakness to Fire-type Pokemon that don't fly. 
• Megahorn hits the hardest on defense, but Escavalier might faint before it can use it. 
• Acid Spray is meant for PvP. 

Counter is generally more valuable as it provides relevant coverage, superior damage output, and better energy generation than Bug Bite. 

Aerial Ace costs the least amount of energy, though 45 isn't exactly cheap either, and enables Escavalier to wall opposing Grass and Bug-types. Drill Run provides wide coverage, including against Escavalier's only weakness to Fire Pokemon. Megahorn benefits from STAB to deal considerable damage, though its coverage may be more niche.