I have noticed that if you apply a rotate or skew on a parent element then to reverse it you can simple reverse the value on the child (simply putting opposite signs to the value, like if it is -10 for parent make it 10 for child).
//transform applied on parent
transform: rotateX(10deg);
//the following works on the child to reverse the transform
transform: rotateX(-10deg);
However when you apply multiple rotate or skew (or their combination) transforms you can not use the same method to reverse the values. Which means there should be some logic behind finding the correct reversal value. Please let me know how to reverse if you have applied rotate or skew (or their combination) on multiple axis such as
//if parent uses any transform similar to the following how can I reverse it on the child?
transform: rotateX(10deg) rotateY(15deg) rotateZ(5deg);
transform: rotateX(10deg) skew(15deg);
transform: rotateX(10deg) skew(15deg, 5deg);