Everyone was frozen in time, but as for why they could still think and hear? It was because he allowed them to think. He wanted every lifeform he killed to remember him, to remember the despair they felt.
Nexus hated everyone. Though Chaos Beasts were considered mythical and powerful, that was exactly the reason why many supreme powerhouses sought them out and captured them. Every cell of a Chaos Beast was an ultimate treasure.
Nexus was the king of the Chaos Beasts. That's why he never showed mercy to anyone, because no one would show him mercy if the opponent was stronger than him.
Victor Alucard—he was the one who was now in the most despair. The Primordial Vampire Clan had existed for eons, and he had only heard about Chaos Beasts as myth as of today.
Even the myth was terrifying. The Chaos Beasts were born from the essence of primordial chaos, and they were born as Tier 13 lifeforms.