Excalibur (エクスカリバー, Ekusukaribā?), differentiated from the Excalibur of Fate/stay night as Excalibur Proto: Sword of Promised Victory (約束された勝利の剣, Yakusokusareta Shōri no Ken?) in Hanafuda, is a Divine Construct and the golden holy sword of King Arthur. Differing from that of Saber's Excalibur, it is a double-sealed weapon locked by two seals, Invisible Air and the Restraints of the Round Table. It is the shining holy sword that saves the planet. A golden blade that repels pretty much any evil, built to defeat an outside enemy that destroys the planet.
If seven or more seals are released, the sword's true power as a Divine Construct to save the world is released, but otherwise, it still acts as a powerful Anti-Fortress Noble Phantasm. The seals remain locked until he activates it, causing a series of clanking sounds as the Restraints are lifted one by one. Activated to counter Enki, it releases as an expanding pillar of light that cleaves both the "Star of Destruction" and Archer with a single strike and vaporising the sea.
Even without releasing its True Name, Excalibur is still able to release its slash of light that varies in strength but are all weaker than its Anti-Fortress attack; however, it can be further enhanced in its destructive power by his Mana Burst Skill. One was powerful enough to counter the Sword of Paracelsus Noble Phantasm attack, while another overrided its power snatching ability. With six Restraints released, Excalibur's Anti-Fortress attack was powerful enough to defeat the rampaging Beast after the death of Manaka Sajyou.
In Fate/Grand Order, the sword takes on the shape of when six of the holy sword's "Thirteen Restraints" are released. Although it still cannot display its true power since over half of its restraints (in other words, seven or more) have not been released, even so, this is unmistakably an intense light that defeats a great evil. The release of the "Bedivere Restraint" is automatically being acknowledged, making one consider the hypothesis of a decisive battle against a greater being.
- Fate/Grand Order Profile of Arthur Pendragon, translated by Master of Chaos at Beast's Lair.
- Fate/Prototype: Fragments of Blue and Silver - Volume 5: Whether it is a battle to use the Holy Sword of the planet, the Divine Construct to save the world...Holy Sword, 6 restraints released! Unfortunately, a majority was unable to be reached. A perfect release of the True Name is unable to be realized. Even so, light emits. An Anti-Fortress Noble Phantasm with domineering strength...
- Prototype material
- Fate/Prototype: Fragments of Blue and Silver: Arc 5, Act 5, Part 3-D, translated by PhoenixRising at Beast's Lair.
- Fate/Prototype: Fragments of Blue and Silver: Arc 5, Final Act, Part 3-D, translated by PhoenixRising at Beast's Lair.