Gáe Bolg (ゲイ・ボルク, Gei Borugu) is a cursed spear given to Cú Chulainn by Scáthach in the Land of Shadows. It was created from the skull of a great beast, Curruid, and serves as Cú Chulainn's most famous weapon.
Powers and Stats
Tier: At least 7-B, higher with Soaring Spear that Strikes with Death
Name: Gáe Bolg
Origin: Fate/stay night
Classification: Cursed Spear, Noble Phantasm
Powers and Abilities: Regeneration Negation, Causality Manipulation (The Barbed Spear that Pierces with Death reverses causality so the effect of the target's heart being pierced occurs before the cause of the attack)
Attack Potency: At least City level (Can wound Servants such as Saber and Archer), higher with Soaring Spear that Strikes with Death, ignores conventional durability with Barbed Spear That Pierces With Death
Speed: None, depends on wielder; can be thrown at Hypersonic+ to High Hypersonic speeds
Durability: At least City level, likely higher (Can survive the explosion caused by Soaring Spear that Strikes with Death).
Range: Extended melee range, Hundreds of Kilometers when thrown
Weaknesses: The Barbed Spear that Pierces with Death can be survived through sheer luck.
Gáe Bolg: Barbed Spear that Pierces with Death: One of Lancer's two Noble Phantasms utilizing Gáe Bolg. When used in this manner, as a single-target sure-kill technique, it reverses causality so that the cause of the spear being thrust comes after the effect of the opponent's heart being pierced. As long as the Noble Phantasm's true name is released, it strikes its target without fail, even if they use a technique that reverses time. When it strikes, Gáe Bolg fills the target's body with thorns and destroys it from the inside. It is described as causing damage equal to the opponent's maximum health plus the damage of the spear, always striking the "heart". While it is powerful, those with a high degree of luck and/or divine protection can survive, as Gáe Bolg misses its mark.
Gáe Bolg: Soaring Spear that Strikes with Death: The true use of Gáe Bolg, and Lancer's strongest attack. It converts all of Lancer's magical energy into raw power, which is released with a throw of the spear, using the full potential of Gáe Bolg's curse. Unlike the Barbed Spear, it does not have the property of reversing cause and effect to always pierce the heart, but its power and range are instead greatly increased, and it cannot be dodged or blocked under normal circumstances, requiring the use of a shield specialized in protecting against thrown spears to hold it back. Even if it is somehow dodged, it will still strike its opponent, homing in on them.