Ye Xiao made the decision to use the ability he received from the Bloodline of Calamity because of his family.
If not for the fact that his family was in the Heavens and needed Heavens' protection, he would not have chosen to take the risk of his body exploding into pieces just to face an enemy that he could not face at all.
He was overpowered in the Heavens, but in front of the coming enemy, he was even less than an ant.
For the sake of his family's safety, for the sake of his loved ones and friends, for the sake of the universe he fought to save before, Ye Xiao had no choice but to take a risk again.
Thus, he told the Heavens that he has a way to face the enemy which shocked the Heavens greatly.
Heavens doubted Ye Xiao's intention at first but when it was sure that there is no way Ye Xiao was thinking of escaping by himself, it heaved a sigh of relief and asked Ye Xiao how he was planning to face the Being of Chaos all by himself.