Mathamune

The Mathamune is a legendary katana shown in Awesome Land VI: Dawn of a New Era. It has a sparkling, multicolored blade and a sky blue hilt with an embedded abacus. Although its origins are currently unknown, its powers are well documented, and it was deemed dangerous enough to warrant being locked away in the unnamed alma mater of the Immortal of Space, Artemis, before its theft at her hands.

The Mathamune imbues its wielder with expert level knowledge of Mathemagic. In the hands of someone who is already well-versed in the subject, the Mathamune is said to bear catastrophic power. Artemis has been shown to use Calculus level Mathemagic while wielding the sword and was able to effortlessly reduce a three-dimensional building into a two-dimensional surface.