Harvey saw the tragic ending of the child that came out of the cocoon. He did not know what sort of principle is at work. But he felt saddened as the woman with silver hair does.
Before the child died, it sang a series of words. It might be a tribute of sorts, but Harvey just did not understand them. All he could tell is that it was a completely new language than the one the attackers used. And this language is older or more profound, evident with how the mana responded and executed whatever the child was singing about.
As the child sang and sang, its body slowly disappeared. Each end of their limbs was turning red and became a speck of mana, slowly being carried away by the wind. Not finishing its song, the child was no more as the silver haired woman held upon a single twinkle of red mana. Tears overflowing in sadness and pain.