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 Restraints of the Round Table.
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. Expanding larger than the city, it can even be witnessed from space.
- ↑ Fate/Prototype: Fragments of Blue and Silver Vol. 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 releasing of the True Name is unable to be realized. Even so, light emits. An Anti-Fortress Noble Phantasm with domineering strength...