Descriptions 101

[TheoreticalSelkie]

@Noblejanobii
Iiiiiii think there's a few candidates for what you may be thinking of. Here's the possibilities:

• Dainslief - personally what I think may be the closest one since it has the possibility of getting rid of your immortality spell.
• Tyrfing - Mainly because of this line: "The dwarves made the sword, and it shone and gleamed like fire. However, in revenge they cursed it so that it would kill a man every time it was drawn and that it would be the cause of three great evils. They finally cursed it so that it would also kill Svafrlami himself."
• Hydra blood - while not exactly a sword or weapon, the weapon could have been dipped in Hydra blood, though I'm not sure if that would negate immortality.

If those three don't work, I can do a bit more searching.

[Noblejanobii]

Hydra blood was probably what I was thinking of but you went above and beyond what I was looking for which works! Thank you!