Max Bond Craft Essence (Saber-Bedivere): My Long, Lost Right Arm
The sparkling silver arm, Airgetlám.
It was originally the prosthetic of a certain god. In Celtic myth, the war god, Nuada, used this arm as a replacement, when he lost his own amidst a great war. The god of medicines, recovery and craftsmanship, Dian Cécht, gave birth to this construct of divine militarism.
To replace Bedivere’s right arm, which had been lost, this arm was then created. Of course, this is not Nuada’s arm. By giving the name of that arm to this one, they could back up the existence of this arm, creating a temporary Noble Phantasm. The true identity of it is the holy sword, which was not returned to the lake.
However, eventually, that sword was safely returned to that lake. Because of that, when Bedivere arrived within the Throne of Heroes, a special case was made. That which resides in his right arm is no longer that holy sword.
Rather, it became an imaginary construction of the holy sword, that is no longer a Noble Phantasm that eats the soul. The bond which binds a Servant and his Master will allow it to be activated. In that sense, it is a brand new Noble Phantasm.