History
Gram was the sword which was forged by Regin Hreidmarson to be the bane of Asgard in retaliation against King Loki's murder of his brother, the shapeshifter Otr, and also to kill his brother, Fafnir, for his greed. Regin gave the sword to Sigurd, in order to kill Fafnir, and, bathed in the curse of Andvari's gold that flowed through Fafnir's veins, became entrenched with extremely powerful "truth magic". It was locked for eons by Odin in a special vault which required five keys to be opened, and it was meant to be for Loki if he be worthy.[1] The five keys were infused by Odin with the powers of "journeys", "endurance", "secrets", "new beginnings", and "brotherhood", respectively.[2]
In modern times, Loki gathered the keys and used it to open the vault and reclaim the sword as his own.[2]
It is said that Gram is capable of piercing any lie with its "truth magic".
Sigurd briefly usurped it from Loki as he went to "Kaluu", truly Mephisto, seeking to use its "truth magic" to provide a means to transfer religions and avoid the fate for him from the Disir. Failing in this, but being saved from a contractual torture, by Loki, he lost Gram once more before being sent to Asgardia.[3]
As Loki learned, his future counterpart was immune to its effects, since the sword only could cause the pain of truths one denied to him or herself, and King Loki did not hide his true nature at all.[4]