Chakas really changed over the Course of these books which we can especially see as we read the second book through his own eyes,

 At the beginning of these stories we see a young, ignorant thief, not really capable of doing anything great. As we follow along the book we start to see progression in his character. it all seems to start when his Geae first starts to affect him. on the island within Damonkijin Crater he starts to talk to the Diadact, seeming to give him advice, when for the duration of the book it had been the other way around. then as they visit Charrum Hakkur, the spirit truly comes awake, and instead of thinking and talking with others, Chakas seems to starts arguing with himself. He develops Knowledge of everything that ever was before humans were de-evolved, but not only the knowledge develops, we start to see this hatred bursting within him, hatred towards the Forerunner for all they had done. This took his distrust of everything even further.

On the Halo, we start to see him take on a Responsibility, of helping the old man, and the young woman survive, for it was him dragging them along. He also starts to trust things around him, with the exception of gaining the knowledge of what is safe to trust, and distrusting what is not. as his Knowledge seems to expand, so does his personality, going from, hating, distrusting, and scheming, to Knowledgeable benefactors of those around him (what is good and bad for him), Knowing how much he can trust things before they betray him, and Strategic survival, looking for each possible best route as he tries to survive the ring world.

One could say he went from being an ignorant Child, to a very Wise man in a Child body. Of which he did, he became not only the Voice inside of him, but his own voice through that.

A nice little tag on, we see that this book was told in a First Person Narrative, as was the first, so we really do get to see inside the character's head, furthering our understand of what exactly was going on in there