The nobles could create the Elven Music Box. Still, the design was ingenious.
The "Shining Era" didn't have any copyright protection. What could one do if others could create it?
Butler Karu spoke with admiration.
"The sacred-blood dwarf is indeed worthy of the blood of the gods. Its knowledge is admirable.
"They came up with a few remarkable methods.
"First, they used a unique energy source to compress the elemental energy into the crystal.
"One can only use our Elven Music Box by purchasing energy from us.
"It will cause damage to the Elven Music Box if the energy source is inappropriate.
"Second, complicated magic array uses the knowledge inherited by the gods. Only the Dwarf God can understand it. It's superbly arduous for outsiders to crack it.
"Third, the fixed upgrade of the magic array. You can upgrade it for free once every six months or a year following the description of it.
