Demise had stalked off, allowing Girahim to get his rest.
Perhaps he'd let his anger get to him today, but truth be told, he liked the scent of blood. The beings that Hylia so loved were not worthy of this land. Demise had it in mind to raise up stronger creatures, primal beings that would suit the land better.
He and Hylia were created by the Golden Three to keep order. To remake the world in the way that he had in mind would be usurping the Three themselves.
Demise's sword would heal. If he could convince him to agree... they could make this land into a beautiful dark land of demons. Any humans that were not strong enough to adapt were not worthy to survive.
Perhaps power had gotten to him, and was making him mad. No... Hylia was the mad one.
Demise would take her inevitable scolding for now and keep his thoughts secret. He wanted his sword in top health, and, for the moment, he didn't want an outright war with Hylia, which he knew would happen if he became too forward. He'd experiment in creating creatures in his image under the cloak of darkness, in secret.
He looked back to the tower with his chamber window. Girahim was going to have to get tougher.