To complete the 'What Goes Around' quest in Arc Raiders, players must destroy any ARC enemy using a Fireball Burner, which is a rewarding quest that offers a full outfit as a reward.
The Fireball Burner can be found by defeating the Fireball ARC in specific locations, including Water Treatment, Research & Administration, and Control Tower buildings in Dam Battlegrounds.
These high-tier level ARC enemies are identified by their appearance, resembling a ball with a blue scanner in front of it.
Author's summary: Complete the 'What Goes Around' quest in Arc Raiders by using the Fireball Burner.