Light and Dark Shadows, one bright and one dark, they were both personally cultivated and trained by the Hidden Clan's ancestors when not needed. When needed, they would appear in public instead of the uncle!
Each Great family's Young Master of the Hidden Clan had the Light and Dark Shadows by their side. Once the Young Masters came of age, the Light and Dark Shadows would, via a Secret Technique, alter their appearance and skeleton to resemble the Young Master exactly. Moreover, the Light and Dark Shadows' strength was mostly higher than that of the true Young Master, and they would only follow the commands of the Young Master, never betraying them!
Among the Light and Dark Shadows, Guang Ying would appear in public when needed, replacing the Young Masters, while An Ying would always follow in secret, ensuring the safety of each Young Master!