Sacred sword

The Sacred Swords are four legendary weapons in Sonic and the Black Knight. They are used to dull Excalibur's scabbard's power during the battle with King Arthur, and to form a barrier around the castle and Merlina's power. These swords are; Lancelot's Arondight, Gawain's Galatine, Percival's Laevatein, and Sonic's Caliburn/Excalibur.

History
During the first part of the story mode, Sonic defeats each of the knights in turn and takes their swords. After the second battle against the Black Knight, Sonic uses the power of the swords to nullify the Black Knight's immortality and finishes him. Later, the Sacred Swords (and Caliburn) are placed in shrines located in the four corners of Camelot to prevent the spread of Merlina's dark magic: unfortunately the barrier is not strong enough, and fails. Finally Sonic confronts Merlina in the Dark Hollow, while the knights and Nimue look on through Nimue's pool. When all hope is lost, Sonic still refuses to give in. On Nimue's command, the knights throw the Sacred Swords into the pool. Caliburn merges with the other Sacred Swords and transforms into the legendary Excalibur, with Sonic becoming Excalibur Sonic, before entering the final battle against Merlina.

Arondight
Arondight is Lancelot's sword. Arondight is a dark-colored sword, with a semi-serrated edge and a strange pattern near the point. It is wielded in Lancelot's backhand grip, and is taken by Sonic after their first fight.

Arondight is sometimes referred to as the Sword of the Lake, due to Lancelot being the Knight of the Lake.

Ddraig Goch
Ddraig Goch is Lancelot's ultimate sword.

Galatine
Galatine are Gawain's twin swords. The Galatine swords are deep red with a bright outer blade. The Galatine's being two swords is to complement Knuckles'/Gawain's close-quarters combat style.

Flamberge
Flamberge is the final weapon of Sir Gawain.

Laevatein
Laevatein is Percival's sword, a rapier. Laevatein is a very thin blade. It is the only sword besides Caliburn to be wielded normally; Arondight is wielded backhand, and Galatine are two swords.

Joyeuse
Joyeuse is the final weapon of Sir Percival.

Caliburn
Caliburn is Sonic's sword. Caliburn's hilt is a bronze color, while most of the blade itself is white. Caliburn is hidden in a cliffside deep in Misty Lake, similar to the Sword in the Stone of Arthurian legends. Caliburn is the only sword wielded by Sonic, unlike the Knights of the Round Table which can forge different weapons.

Excalibur
Excalibur is the transformed state of Caliburn. Unlike Caliburn, Excalibur is all gold, even holding a golden outer blade.

Long Lost Light of the Sacred Swords
The Long Lost Light of the Sacred Swords is the holy power from the swords that was summon to aid Sonic when he fought The Dark Queen grant Caliburn the power to become his true blade, Excalibur. It also gave Sonic a golden armour which granted him powers such as flight and invulnerability. The light could of been unlocked when the swords were at the Sacred Shrines and when Nimue's mystic well shines with the light, asked the knights to offer their swords to allow Sonic to have the light.