Angel of Tribulation

At the end of the universe, Zhang Tianze, who was trained as a tool, relied on his grandfather to help him escape the pursuit of heaven, and relied on his heaven-defying martial spirit to escape his fate as a tool. By chance, fellow Buddhists, Taoists and demons started to stand in the way of killing people and killing Buddhas. So why is he being hunted down by Heaven? Who was the enemy who massacred his parents? How did he save the universe in the end? If you want to know the reason, please listen to me slowly.