The Blade of Bastet is based on the iconic weapon of the same name used by the fictional hero the Mistress of Mystery. The Order of Mysteries fabricated these recreations using historic swords, such as Grant's saber, and the swing analyzer modification after it has recorded the wielder's sword fighting stance and style.
The Blade of Bastet has +50% armor penetration, but with the Eye of Ra also equipped, this increases to +100% armor penetration.
Crafting a Blade of Bastet requires a Blade of Bastet as one of the materials, and it cannot be crafted without one. This also applies to the upgraded levels, each requires the prior Blade of Bastet to make the improved version.