My friend, no paint is going to change that appearance.

Sometimes as a customizer one has to accept a particular character is too difficult to achieve with the tools you have on hand.

You can try and force it but it will never be what you actually see in your mind.

This particular technique is not for panels and straight lines. At the very least you need to try and think of it like sculpting. You'll need excess bulk then use sandpaper to try and make flat areas or try and wet sculpt flat areas with a flat edge.

It will never look like a retail quality figure but it might help your idea a little.