Chalce's theory about Artificial Soldiers is that they are able to manifest human emotions after receiving education and also part of the memories from another person. His memories were implanted in Agate and Chrome.
Later on his diary was found, revealing more about his past. "Agate" was originally the name of his private artificial soldier but since Chalce taught him to speak and many other things, he became much more - his first friend. When his father did not approve of their friendship and tried to destroy Agate, Chalce interrupted and accidentally killed his father. Chalce met the new "Agate" on a few occasions, last one being the moment when his plane was shot down.
