Muramasa Sengo was a swordsmith in 16th century Japan. Though an excellent swordsmith, he was said to be insanely ill-tempered, verging on just straight-up insane. This trait led to myths that swords made by him were cursed with the same afflictions
, encouraging the wielder to fight to the death, and would, if no battle was present, turn on their owners and compel them to commit suicide.
These rumors weren't helped by the fact that Shogun Tokugaya Ieyasu banned Muramasa blades because many of his friends had been killed by them, and that he had accidentally cut himself badly with one.
In fiction, Muramasa will usually be a rival of Masamune
(Never mind the fact that they didn't live in the same time period
) as well as Always Chaotic Evil
. A legend regarding both swordmakers said that if you put one of each of their blades in a stream, leaves floating towards the Masamune would drift safely around the blade, while the Muramasa drew leaves to the blade, whereupon they would slice themselves in half
His swords will usually be Empathic
(Possibly even absorbing blood into the blade to strengthen itself, or encouraging the host to do so by cursing them.
) and have an Obviously Evil
appearance aura about it (Notches, rust, bloodstains, ect.) The blade may alo take near inhuman force of will to sheathe the blade once unsheathed until blood is drawn with it. In sharp contrast to the swords made by his rival, If a character reveals they use either of these, expect the Muramasa user to be evil, or at the very least, morally grey
, and the Masamune user to be good (most of the time