Legends: The Emerald World

Cultivating his power by slaying demons and taming countless beasts, the emperor solidified his throne as the world's ruler. But not once in his life had he expected that his disciples would use research on demonology to sap the world tree's power and push the world to destruction.
Trying to fix his mistake, he opted to use all of his cultivated power to cure the world tree and block anyone from sapping its power ever again. But in exchange, he was to lose all of his power.
But...the worst had happened, his wife... had betrayed him.