How do you implement wolfman or a new skill?

[Dafuq313 2]

I want to understand how you can add a new skill and by seeing how to implement the wolfman I should get an idea, the thing is, in source there is nothing and as I understood the skills are defined somehow in skil.proto but I just don't understand how, for example, where does it say that ninja is invisible when using camouflaje until he attacks? I would expect that that should be defined using C++.

What I am asking for is only the parts that are necessary to implement wolfman, not the whole files though so I can see what I modify.