Before this conversation, Adam didn't even know that there were any other hybrids in this world besides Nessa. It wasn't something he thought about much, as he believed that Nessa was the only one of her kind.
However, if he had thought about it after learning about the World Wipe and that the strongest monsters could easily live for several thousand years like humans, he might have realized that it was strange that Nessa was the only Hybrid.
Even if her case was unique and difficult to replicate, the chances of something like that never happening in hundreds or even thousands of years were too small.
However, none of that mattered anymore, because now Adam was learning information from someone who knew more than most people in the world.
There were hardly any secrets that Damien didn't know about. He was too powerful and had lived in this world for too long for anything to remain a secret from him.
