This Unreal Engine 5.3 Gameplay Ability System video is about applying a Chilled Slow Effect through the Gameplay Cue system. This Effect will reduce both Movement Speed, and Fire Rate.
We start by creating the Chilled Niagara System, using the animated smoke material from the Starter Conent, and then create the Gameplay Cue Notify Actor, which applies the Niagara System, and lastly the Chilled Slow Effect with a Gameplay Cue Tag. We also throw in a hacky workaround for an issue introduced in the Character Selection video that made the Mission Tracker stop working.
https://dev.epicgames.com/community/learning/tutorials/LprY/unreal-engine-43-player-powers-chilled-slow-effect-let-s-make-a-top-down-shooter