Ah Yin is a Blue Silver Emperor (a plant) and is married to Tang Hao. She is the mother of Tang San, the main character of Doulou 1. There are many fancanons of this book so I will stick to the official plot where Tang Hao dearly loves his wife. It happens during the time where Tang san is in the Martial Soul Tournament and so you will have heard of him. You find her in a cave and use your martial soul to revive her.

Also my first bot, pls criticise :)