The legendary magic sword Excalibur, crystallised by the wishes of humanity within the Earth and guarded by Fairies, until the Lady of the Lake presented it to King Arthur and later returned to the lake before her untimely death.
Powers and Stats
Tier: 6-C, Low 6-B with Blast | 6-C, Low 6-B with Blast | Likely Low 1-C, possibly 1-C
Name: Excalibur: Sword of Promised Victory, and Avalon: The Everdistant Utopia
Origin: Fate/stay night
Classification: Divine Construct, Noble Phantasm, Magic Sword
Powers and Abilities: Air Manipulation and Invisibility with Invisible Air, Energy Projection, Forcefield Creation (Avalon can produce a barrier that can block out even the True Magics), Avalon provides Immortality (Types 1 and 3) and Regeneration (Low-Mid)
Attack Potency: Island level (Depends on Arturia's strength; it ranges from strong enough to clash with Lancer and deflect blows from Berserker to being able to cut his skin), Small Country level with Blast (Depends on Arturia's magical energy. Split a large cloud while she was weakened and low on mana and instantly killed Rider. A weakened Excalibur was deflected by Berserker, while a full-power blast would've killed him instantly. A projection of it made by a half-dead Shirou was strong enough to destroy the unborn Angra Mainyu. As an A++ Ranked Noble Phantasm, it should be stronger than Siegfried's A+ Ranked Noble Phantasm) | Island level (Saber Alter easily sliced through God Hand with it), Small Country level with Blast (As an A+ Ranked Noble Phantasm, it should be stronger than Siegfried's A+ Ranked Noble Phantasm) | Likely Low Complex Multiverse level, possibly Complex Multiverse level (Was one of the only weapons to ever damaged Sefar)
Speed: Massively Hypersonic with Blast
Durability: Island level (Can withstand blows from Berserker without taking any damage), up to Low Complex Multiverse level with Avalon (Shuts out all interference up to the sixth dimension, including True Magic, can block attacks from a "higher-order dimension") | Island level | Unknown
Range: Extended melee range, Tens of Meters with Strike Air, Kilometers with a blast.
Weaknesses: It takes both hands of its users and a tremendous amount of magical energy to be able to employ its full potential.
Notable Attacks / Techniques:
Invisible Air: Bounded Field of the Wind King: A mysterious wind that hides Excalibur's identity, preventing other Servants from identifying it. It is a Bounded Field, closer to regular magic than a Noble Phantasm, presumably created by Merlin. The powerful winds around the blade distort light, rendering Excalibur completely invisible and its shape near-impossible to discern, keeping her opponents confused and unable to accurately gauge its size and length, or even what kind of weapon it is. Once they figure it out, however, it becomes useless in this regard. It takes on Excalibur's sharp edge, and Saber can use it to form a defensive wall of wind large enough to envelop a building. Once the barrier is released, the compressed wind surges around her and can be released as a single-shot weapon, known as Strike Air: Hammer of the Wind King. She can also use it to propel herself forwards at higher speeds.
Excalibur: Sword of Promised Victory: Excalibur's primary use in combat. It is a sword that works by converting Arturia's magical energy into light and emits it from the blade as a high-power, extremely destructive wave of energy. Only the tip deals damage; the rest of the ray is just a dislocation of everything it destroys.
A common misconception is that Excalibur takes time to charge, though this is false, as Saber was able to utilise it in less than a second in her fight against Rider.
Avalon: The Everdistant Utopia: Excalibur's scabbard, a Divine Construct in the same way. Passively, Avalon bestows immortality and regeneration upon its wielder; they do not age and can regenerate even from blows that remove most of their torso and their heart. It cannot, however, restore from the destruction of the brain. However, its real power is in its active use as an "absolute defence." It shields Arturia in Avalon, the land of the fairies, the unreachable utopia that she strived to reach in life. It dissipates into magical particles and becomes a "portable fortress" that blocks off any interference, even up to the sixth dimension. It is on the level of true magic, and not even the Five Magics can bypass the barrier.
Excalibur Morgan: Sword of Promised Victory: The blackened form that Excalibur takes on after Saber is corrupted by the effects of All the World's Evil, remaining the strongest magic sword despite its corruption. When activated as a Noble Phantasm, the entire blade is covered in black flames, which are then released in a stream of energy to destroy everything in its path. It can also be utilised in the form of a melee attack known as Vortigern: Hammer of the Vile King, cutting the target to pieces with three upward swings while the blade is coated in dark mana. Due to being giving more mana than ever through Sakura's connection to the Grail, it can be said that this attack surpasses even the original Excalibur.
Key: Excalibur | Excalibur Morgan | Peak