The first of the Muramasa Blades, the Black Blade was created centuries ago by Muramasa. When Muramasa forged the weapon, he placed a piece of his own soul inside of it. By this act, the blade was infused with mystical powers. As a result, whoever wielded this deadly weapon would be granted invulnerability and superhuman strength. However, these abilities come at a price; if the wielder of the Muramasa Blade possesses it for too long, then he/she will become overwhelmed by Muramasa's mad soul.
Muramasa created the second blade for Wolverine because Logan wanted to exact revenge upon the people who killed his wife, Itzu. This blade is made of the same Japanese steel as the first, and it is just as durable (although not indestructible). Unlike the first blade, the second blade does not grant superhuman powers. Instead, its cuts negate superhuman healing factors. For example, when Wolverine wielded his Muramasa blade against Sabretooth, the blade's powers inhibited the use of Creed's healing abilities. Following a battle between Daken and Wolverine, the blade was split in two. The lower portion and handle remained in the possession of Wolverine, but the broken distal portion was collected by Daken. Romulus hired the Tinkerer to process the metal and coat Daken's wrist claws with it to grant him the ability to kill his father (and others with healing factors). After defeating his son, Wolverine removed Daken's Muramasa Claws and buried them with the Muramasa blade in an unknown location.
What If...? Wolverine: Father
For more information see : What If? Wolverine: Father
In this What If...? story Wolverine is there when Draken is born and becomes the boys father. But later Draken's life takes a dark turn and Wolverine is forced to use the Muramasa Blade to kill his son and himself.