How to get "Local Illumination"

Hi all, still somewhat of a newbie to unreal. I’m aware of the limitations of LPV for dynamic point lights, but I have a game where the player fires crystal projectiles that illuminate an otherwise completely dark cave, and I am wondering if there’s some kind of post processing trick or something to get some “lighting”! in the dark areas of the attached photo. The problem is that the player can fire these anywhere and if they happen to fire one in the wrong area then only a small space will be lit and everything else will be sharply black. Having constant GI everywhere wouldn’t work since the unlit areas need to be completely unlit. Any ideas?