User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-184612-20141016003459/@comment-22748142-20141016095025

As you upgrade the wyvern stone store, you will unlock additional wyvern stone to use. there are 4 stones : Def up, Attk up , Enable status attack , faster purify ( aka clean the virus out of the monster faster )