Upon achieving longevity, Lin Zhen did not immediately relax.
This was because inside his body, his Black Hole Devour had mutated after swallowing a new black hole!
A black hole can only have one Naked Singularity.
No one knows what would happen when two Naked Singularities exist within a single black hole.
Lin Zhen, too, hadn't considered many scenarios when he swallowed the Naked Singularity. He merely hoped this act would enhance his energy, making his breakthrough a bit more potent.
Thus, the new Naked Singularity became part of Lin Zhen's Dantian, an integral part of his black hole.
But the two Naked Singularities clashed.
The original opposed the newcomer, who didn't wish to obliterate itself, but instead wanted to devour the original.
Lin Zhen, of course, couldn't let the new one devour the old one. And with his help, the old Naked Singularity won.
But the newcomer didn't meet its end.