Existence

A brief description of the manhwa Existence: One day, it was a herd of ants, and another day, it was a large dinosaur.
This was the last reincarnation of a being that had experienced tens of thousands of reincarnations and lives. He was born as a human with the power of every single lifeform he had ever been. Why did he have such an ability?
Lee Jain finally came to understand. “I exist to eradicate mankind.”