"The sole Demon..."
Such an explanation from Aniye not only failed to clarify things for Rocky, but instead confused him even more. All he could do was to try to understand the statement literally, "Master, are you saying that this Demon named Leviathan, there's only one in the world?"
"That's correct."
Aniye nodded, indicating that Rocky's literal interpretation was entirely correct—the Demon named Leviathan was indeed a singular existence in the world!
"Can there really be... such a thing?!"
Faced with Aniye's affirmative answer, Rocky was stupefied because this answer obviously overturned his common knowledge about Demons!
What does 'unique' mean?
Only an independent entity could be described as unique, just like humans; each person is unique to some extent. Rocky and Aniye are both humans, but you can't find a second Rocky in this world, nor can you find a second Aniye, that's what 'unique' means.
But how could you describe a Demon as 'unique'?
