Talk:Great Tomb of Nazarick/@comment-98.157.155.87-20150417054846/@comment-26181040-20150417225019

I suspect those magic crystals are rewards or residual prizes that players receive after killing high class monsters in Yggdrasil. These crystals are valuable as they are basic programming components to customize NPCs, weapons, artifacts etc. It was explained in volume 3 that they are kept in the treasury.