"So, tell me! What is the cost of such a perfect method?"
If there were such an easy method in the world, Herbert believed that Nenasha wouldn't have deliberately kept it a secret before, not mentioning a single word.
Then, surely, there must be some cost involved.
"Does it require some special materials?"
["It indeed requires them, not just anyone is qualified to build it, but for someone qualified like you, it shouldn't be difficult."]
An operation of this level is not something that can be done simply by knowing the method; even if ordinary people know the method, they lack the ability to execute it.
And Herbert has this qualification purely because he is an ally of Nenasha.
["But having the qualification alone is not enough, to build the Heroic Spirit Pool, you need at least two more things."]
["One is a part of the remnants of the original Heroic Spirit Pool."]
