seems the more magic power you pour into it the longer it will last.
However, it sure is plain.
I do feel that it's a bit of a stingy reward for the experiment's first phase...
"That magic circle is something that no one at the magic guild can use, it's an original of the person I was talking about before."
"Oh, is that how it is?"
Zapanizu whose heart dances when told it's a limited item. [13]