Reyna’s ultimate, Empress, buffs her by increasing her firing rate, reload speed, and the speed of switching between guns and abilities.
It’s basically a button that lets her go absolutely HAM – when used properly she can often take out multiple enemies by herself.
Outside of her buffs, she also outlines enemies similar to how Viper does when within her Viper’s Pit ultimate.
This makes it easier to hunt down enemies as you can see them more clearly from far away and behind corners.