Gáe Buidhe

This is the cursed spear that inflicts wound that cannot be healed. The spear lowers the max HP limit, thus any healing magecraft or regeneration ability will only recover it to the point where it has received the injury. This cannot be dispelled, and cancelling the curse requires to destroy the spear or kill its owner, Diarmuid.

The golden spear is 1.4 meter long, and is normally wrapped in a talisman cloth. This demonic spear was given to Diarmuid by Manannán mac Lir, the king of fairies.

The "buidhe" in the name means golden.

Sources: Fate/Zero vol. 3 status page and the dictionary resource at Jonnobi.