Reasons why Jiang Yuyan can substitute flowers for trees;
"Replacing wood with flowers" is the ninth priority of the peerless martial arts "bridging suit" of the Flower-moving Palace. Hidden in the "six-person dice" opened by her daughter Jiang Yuyan, and enchanted. Successfully absorbed the internal force of the moon-inviting star and seriously injured Yan Nantian.
The death of Jiang Biehe:
Yuyan asked Hongye to tell Xiaoyu the secret of Jiang Biehe and Wuque, and then tipped off Jiang Biehe. As Yan Yu expected, Jiang Biehe asked her for help. Yu Yan laughed at Jiang Biehe and studied the peerless magic in "Six-person Dice" by herself. In order to practice magic, Jiang Biehe gave up his martial arts and became a cripple, only to know that he was designed by Yu Yan. Yu Yan performed in front of everyone.
Extended data Jiang Yuyan ending:
Xiaoyu came up with a plan of mutual destruction. Under the stress of small fish and impeccable, Su Ying said there was a kind of "poisonous king's holy water". After taking it, Yu Yan was induced to absorb internal force, which could kill her.
When Su Ying went to get the medicine "Midnight Magic Orchid", he was accidentally bitten and poisoned. After preparing "Poison King Shui Sheng", Su Ying died of poison. Xiaoyu was lovelorn again, and the pain in his heart made him collapse.
Five steps and little fish draw lots to decide who will destroy each other. Five steps draw lots. When drinking farewell wine, Xiaoyu made sure that he couldn't move with hemp boiling powder and left by himself. Fish lured Yu Yan to absorb her poisonous internal force, arrived in time without any defect, and finally killed Jiang Yuyan.
References:
Baidu Encyclopedia-Fish and Hua Wuque