The simplest way to do this is, for example, like this (I'll explain using the Archangel Sarah as an example):
- In the hero's file, set the specialization line to HERO_SPEC_NONE, i.e., make the hero without a specialization.
- Rewrite the paths to the new icon and text files for the specialization.
- Name the specialization "thick-skinned."
- In the description, write "+2 units to the hero's physical defense."
- In the hero's file, increase the defense parameter by 2 units.
Done!
http://ru.ashan.wikia.com/wiki/Сара