Cursed Gear

A Demon Curse (鬼呪,) is a spell considered to be the most difficult of all magics. It serves as the foundation for Cursed Gear (鬼呪装備,).

The kiju is a important element in the Seraph of the End: Guren Ichinose: Catastrophe at Sixteen light novel series.

Cursed Gear Creation
Creating cursed gear involves directly calling on Bodhisattva, black demons, or other supernatural entities and sealing them directly into sacred items so that they could serve the wielder.

The items used to seal demons are almost exclusively weapons: swords, axes, and even bows.

The weapons need to be consecrated and purified - a process that takes years before a demon could be trapped inside.