The Slinger can activate environmental hazards such as Flashbugs, Boulders, and traps. Its control appears beside the lock-on button when an eligible target is nearby.
Aim at the hazard and activate it while the monster can be affected. Merely triggering it does not guarantee success: a Flashbug behind the monster's view does not blind it.
Environmental hazards can interrupt or stagger monsters and create attack openings. Their location and effect depend on the encounter.