I’m trying to do the same for Z axis too, and I used ToObjectSpace.
x,y,z = char.Torso.CFrame:ToObjectSpace(char.HumanoidRootPart.CFrame):ToEulerAnglesXYZ()
Left Shoulder C0 = Left Shoulder C0 *
CFAngles(XVector + x , -1.55 + y, z), where XVector is the mouse unit
( -math.asin((mouse.Origin.p - mouse.Hit.p).unit.y) )
Right arm works as intended, however the left arm seems to be at the wrong position, any possible solutions?
https://gyazo.com/e915f34a3d4639b880736cfec563ec0c