Bisharp

Bisharp is a unique Pokemon with its Dark/Steel typing, but ultimately its stats hold it back from seeing the spotlight in the meta. At least its shiny variant is quite notable. 

Best PvE Offensive Moveset

• Snarl performs the best, and pairs with Dark Pulse to fulfill a Dark-type role. 
• Metal Claw should pair with Iron Head to fulfill a Steel-type role. 
• Focus Blast lacks STAB and has no use.
• X-Scissor lacks STAB and has no use. 

Best PvE Defensive Moveset

• Snarl is better on defense due to its higher base power and energy delta, but is resisted by Fighting-type attackers. 
• Metal Claw is inferior stat-wise, and not as good for defense.
• X-Scissor is the hardest to dodge, and can be spammed frequently as a 3-bar move. 
• Iron Head is slightly harder to dodge than Dark Pulse, and has less base power, but is not resisted by mono-Fighting Pokemon.
• Focus Blast is too slow for defense.

Snarl is preferred for its high energy generation. Metal Claw is a below average fast move, though it offers more damage output and Steel-type coverage. 

Dark Pulse benefits from STAB, and offers relatively neutral Dark-type coverage. X-Scissor is mostly an option for baiting shields thanks to its low energy cost, though its damage output can add up in prolonged battles. Focus Blast can be chosen for its high damage threat and valuable Fighting-type coverage, but it demands a lot of energy to use. Iron Head isn't very impressive, and Steel-type attacks generally aren't useful against meta Pokemon, but Bisharp runs the risk of being walled by Fairy-types without its coverage.