Armarang

Armarang
This mutation transforms the player's arm into a boomerang, allowing it to be launched as a projectile.. The rapid rate of fire and the damage dealt per throw make Armarang one of the most valuable Exo Mutations. The projectile arm returns from the end of its trajectory if not interrupted by the environment; if it passes through an enemy, it will return through it as well, effectively dealing double damage.

Buzzsaw
Armarang can be upgraded to Armarang Buzzsaw, which enables the projectile arm to stop and spin at any point mid-throw to deal continuous damage in one spot. It is useful for fighting stationary enemies such as Bombshells, Protectors, or Barkley.

Legion
Armarang can also be upgraded to Armarang Legion, which enables the player to throw multiple arms at a time. Along with the original's potential for double damage, Legion allows for even quicker bursts of concentrated damage.