Lady Snail?
Shitou watched Lu Aiguo and Xia Yuan, who were coaxed until they were dumbfounded, a smile flickering in his eyes. If he hadn't been paying close attention to her facial expressions, he might have actually been fooled by her.
In fact, he had been suspicious of her from the beginning.
Her behavior didn't resemble that of a six-year-old child. Even though she sometimes acted childishly on purpose, her eyes and subtle facial expressions betrayed her true feelings.
Moreover, a person's change couldn't possibly be so sudden and so drastic. Brother Aiguo and his wife were blinded by familial affection, so they couldn't see through it.
But if she wasn't Su Yun, then who could she be? Could it be that ghosts really exist in this world and can possess people? Her actions didn't carry any malice; instead, she seemed to harbor intense affection for Brother Aiguo and his wife. Could it really be Lady Snail repaying their kindness?