There is evidence that supports this, the Librarian laid seeds (geas) in Halsey and many others she explains in Halo 4 for Chief achieve he's true potential. If they could devolve the rest of humanity it is quite possible that the librarian preserved Forerunner DNA hidden in Chief and others to preserve their race as they did rightly fear the flood's advance and possibly their existence. It wasn't luck that Halsey picked Chief. It wasn't luck that he was stronger and more intelligent than the other 75 candidates. Forerunner Saga explains about the mutations a manipular goes through and the classes. It's very possible Chief is warrior class and his exchange with the Didact at end after the Librarians earlier tampering finished the chain and started the next step of Chief's mutation. Tbh I find the sucks to be you kind of comment a bit insulting as I know what I have seen, it's easy to edit still pictures and film but I am not saying you are lying. I am not contradicting myself. The source I provided was just an example and in that you can see his full top half of his face, not just a small cross section of his eye. The librarians face in cut scenes from Halo 4 show she has sunken eyes. I take your point about the Didact his were darker and this may be due to what happened to him but either way he had sunken eyes before like all the forerunners (that I have seen). But that is what I love about Halo and Sci-fi, anything is possible. I am not offended it is a debate after all Forthencho. Again it's been fun.