With the help of A_De, I was able to faithfully recreate the angel of darkness climb up animation based off of some of the rotation and position coordinates.
This animation took some time to make, as the one A_De gave me was totally unusable (i.e unecessarily hard to fix), forcing me to recreate it into a new Lara object.
Last but not least, this animation is not meant to be faster than the original. Although it looks smooth to the eyes, it was not possible to make a faster version as the whole weight illusion disappears.
If you use this, please credit SrDanielPonces.
All you have to do is replace animation #97 from your LARA object. No script necessary.
Custom Animations / TR AOD / TR 4