The resurrection of the eagle proved that Yang Jian's previous speculation was correct. He used the supernatural power of the Deceiving Ghost to create a living body, and combined the Ghost Shadow's power to modify others' memories by implanting a living person's memory within. This method could indeed resurrect a person.
Currently, this method seems to have no side effects, and it's much better than using the Ghost Mirror for resurrection.
Resurrecting someone with the Ghost Mirror requires releasing a malevolent ghost as a price, and the memory only remains at the moment of looking into the mirror. It also requires someone to stay by the Ghost Mirror and pull the resurrected person out of the mirror, otherwise they might be killed by the malevolent ghost in the mirror. In other words, there are severe side effects.
However, Yang Jian can only resurrect people whose memories he has stolen; those whose memories cannot be stolen cannot be resurrected by him.
