Luck of the Clan: I Am the Only Mortal Left in the Clan at the Beginning

The whole clan is a cultivator of immortals, and I am the only mortal. At the ceremony, the clan elder announced in public that he was expelling me from the clan because I was dragging down the destiny of the clan. The catastrophe is coming, and the ancestor is about to be wiped out. I stretched out my hand to touch Heavenly Tribulation and whispered: "Rule 17 - Heavenly Tribulation will not attack mortals." The catastrophe has stopped. The whole clan knelt. They don't know that I have a broken genealogy in my hand. Every time I record the breakthrough or death of a clan member, I can tamper with the rules of heaven. But the price of tampering with the rules is my lifespan. The next second, the page of the family tree turned: the next person to fall, third uncle Li Changfeng, had achieved a breakthrough in foundation building, with 72 hours remaining. I only have one chance. Save him, or save yourself? The whole clan is immortal, but I am a mortal. They rely on cultivation to overcome the tribulation, and I overcome the tribulation by changing the rules. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.