Hello there I have done a similar feature using a transform modify bone. Works for first and third person can also be replicated. You create a simple custom event that has a float input. Then create an input for which key you want set it between 35-45 for the float when pressed then 0 when released for right lean then -35-(-45) for left input pressed. Then in your anim graph do a split struct for rotation on the transform modify and plug the lean float you create in your animBP that you set there pretty much copying the one used for your input function from your player character bp. Lerp it set the target whatever your variable from your character is. Use whatever time you want it to take I use 4, then the output is your variable in your anim Bp that you call at your transform modify. Only issue I am having is the players spine rotation is conflicting with the lean spine rotation when looking up and down maybe I can not use the same bone in the sun offset as I do with the lean. The lean only affects the pitch.