|Title:||The Fake Spiral Sword|
Caladbolg II: The Fake Spiral Sword (偽・螺旋剣, ?) is a modified version of the original Calabolg using Reinforcement. Archer encountered the original sword at some point during his life, adding it to the numerous Noble Phantasms stored in Unlimited Blade Works and allowing him to modify it to suit his fighting style. He projects it to be used as an arrow rather than a sword, with the improvements aimed to make use of it as an A-rank Broken Phantasm. He chants the first line of Unlimited Blade Works' incantation before firing it and, despite being renamed with the "II", he still only chants "Caladbolg" to activate it.
The blade of the sword coils into a spiral that can penetrate any target by creating a twisting distortion in space when fired. When fired at Caster, it is powerful enough to easily break through her magical defenses simply as an aftereffect of it being purposely fired at an area far away from her. Shirou believes that, even if she had tried to teleport away from the attack, she would have simply been twisted along with the space as well. After being intercepted by Berserker, it creates a large explosion capable of razing a cemetery and engulfing it in flames. The original is the demonic sword possessed by the hero of Ireland, Fergus mac Róich. It is considered to be the natural enemy of Cú Chulainn, due to having a geas placed on himself making it his duty to be defeated once by the sword if the wielder is Ulster-born. Gilgamesh is shown using the original sword against him in the anime adaption, after binding him with Enkidu.