Through their training, Shingi came to a few conclusions. First, Dark Shadow learned its Skills fast enough that Shingi knew that his INT was over 15 but less than 20. His Scholar Master Profession also affected him because of their bond.
He also learned something about the body of Dark Shadow, which Syra noticed before him and let him know. A thin layer of Spirit Mana surrounded its body, and most of its feathers were made by Spirt Mana, mixed with Dark Mana.
Shingi couldn't understand why the Dark Mana mixed in it, but it could be because of how the egg was created. That egg wasn't naturally made, as somebody sacrificed all those other eggs for it.