Before that, the Murasama was a Revengeance-exclusive weapon dropped by The Devourer of Gods. Prior to being located in Underworld Arsenal Labs, the Murasama was generated in now-removed Underworld Shrines.The weapon's tooltip, "There will be blood!", is a reference to the lyrics of "The Only Thing I Know For Real", which is Sam's boss theme.The fact the weapon is "ID locked" is also a reference to Sam, for the inability of using his weapon immediately after defeating him, unlike the other bosses in Metal Gear Rising.The fast, blurred cutting animation that the item uses is based on the blurring visuals shown when the player or Sam uses the sword.The Murasama is wielded by one of the game's main antagonists, Jetstream Sam. The Murasama is one of several references to Metal Gear Rising: Revengeance, the others being the Boss Health Bar, Red Sun, Excelsus and Revengeance Mode alongside other minor references.The Murasama has a Draedon's Log entry dedicated to it, also found in the Underworld Bio-center Lab, where it is depicted alongside the Phaseslayer.The Murasama only deals 40% damage to Ares and its weapons and 35% damage to Supreme Calamitas' Supreme Soul Seekers.The sword can be used at any point before defeating Yharon if the character's name is "Jetstream Sam" or "Samuel Rodrigues".It's swing range is also fixed, despite the slashes appearing at varying distances. The Murasama's attack speed is slower than what is visually indicated when using it, at 25 use time (2.4 swings per second).As such, it is also has the most range of all true melee weapons.
It possesses a larger than normal critical strike chance.
Although Murasama is technically obtainable in Pre-Hardmode, it cannot be swung until Jungle Dragon, Yharon has been defeated in the current world. It can be found in The Underworld's Bio-center Arsenal Lab, contained within a Security Chest. The Murasama is a post- Moon Lord melee weapon resembling a sword. "It was tempered by the fires which are fueled by spirits, and formed in the magma I draw into my laboratories." Not to be confused with Muramasa, a vanilla broadsword.