Caliburn

Caliburn (カリバーン) is one of the main characters in Sonic and the Black Knight. He is a sentient talking weapon and the legendary sacred sword who protects England in the world of Camelot from danger. He is the one who decides who is to be the monarch of the lands ruled by King Arthur.

Following King Arthur's corruption into the tyrannical Black Knight, Caliburn became Sonic the Hedgehog's partner to stop to Arthur's reign of terror. Though their relationship came off to a rocky start, Caliburn provided Sonic with the guidance and knowledge needed to be a true knight, and together they stopped Arthur and afterwards Merlina the Wizard.

Early life
Many years ago, Caliburn was placed in a stone by Merlin, who claimed that only the true king of England would be able to pull Caliburn out of it. None were able to pull Caliburn free of the stone, until a young Arthur came and accomplished this miraculous feat. This act made him the ruler of all England.

Presumably, though contradictory, Caliburn was once a piece of Excalibur. However, when King Arthur's corruption, caused by the Scabbard of Excalibur, extinguished Excalibur's light, it split into Caliburn and the three other sacred swords. Under unknown circumstances, Caliburn was then placed in stone and came to rest in Misty Lake for a long time.

Sonic and the Black Knight
At the end of the second mission, Sonic pulls out Caliburn. To his surprise, he finds the sword has a mind of its own and can talk. Caliburn doesn't approve of Sonic initially, calling him a "Knave" at first. Sonic likewise didn't get along with Caliburn, calling him an "oversized letter opener" and mocking him at most any chance he got. But the two begin to work together over time. He sticks by Sonic's side throughout the entire game and joins him in battling monsters and the Knights of the Round Table. By the time Sonic defeated Sir Percival, Caliburn "accepts" Sonic and dubs him Sir Sonic, Knight of the Wind. During Sonic's final battle with the recently revealed antagonist Merlina, Caliburn is broken in half by her vicious attacks. Sonic's determination restores Caliburn, transforming him into the legendary Excalibur and transforms Sonic into Excalibur Sonic. They work together and defeat the Dark Queen, the final boss.

In the end, Caliburn reveals that he is the one to decide who receives the crown. The Royal Knights are shocked to realize that this means Sonic himself was the true King Arthur the entire time.

Sonic Runners
Caliburn appears in Sonic Runners as a S Rare Companion, allowing the player's character to perform slash attacks in boss fights.

Personality
Caliburn acts like a proper and polite gentleman and has proud manners, which initially clashes with Sonic's easy-going attitude. He is also shown to slightly have the personality of a strict teacher, usually calling Sonic a fool when he does something that Caliburn disapproves of or disagrees with and is soft on compliments.

Powers and abilities
Caliburn has a sharp cutting edge that allows him to cut through even rock, though with some effort. Over time in Misty Lake, his blade grew blunt, but he regained its edge thanks to the Blacksmith. As a sacred sword, Caliburn possess magical properties, though the full range of them are unclear. He can dispel the immortality granted by the scabbard of Excalibur when combined with the other sacred swords and activate the barrier stones. He is also capable of levitation, allowing him to move around on his own.

Caliburn possesses extensive knowledge in the art of swordsmanship. He is also skilled at teaching swordsmanship, as he was able to teach Sonic enough skills to go head-to-head with the Knights of the Round Table, who are all masters in swordplay, in a manner of days.

Excalibur
Excalibur is a transformation of Caliburn and is, according to Caliburn, his true power. However, this form and its power were locked away following King Arthur's descend. He seemingly regained this form and its powers thanks to Sonic's willpower during their battle with the Dark Queen. In this state, Calburn can cut through anything, repel magic and form an all-piercing energy meteor with Excalibur Sonic.

Quotes

 * You are the Chosen One? You are but a squire!
 * Hmph! The impertinent one is you, Knave! Brace yourself, for I shall train you until you are worthy!
 * We must ask the scabbard's former owner how to hinder its power.
 * Hm... I suppose something must be done about this.
 * My edge has grown blunt. Being stuck in that rock for so long has taken its toll.
 * Fool! A Knight never flees his foe! 
 * Very well then, I shall call you: "Knave The Hedgehog."
 * I am the Sacred Sword, Caliburn!. I am the one who decides who's worthy of the crown 
 * Onward Sonic, Knight of the Wind!
 * Please try not to make a mess!
 * Never underestimate your opponent. Especially when it's a dragon.
 * A worthy adversary.
 * (Defending Sonic from one of Merlina's attacks) You fool! A knight must always be on his guard.
 * Well done.
 * Hm. Actually... Sonic the Hedgehog... You have mastered the code of chivalry. From this day forth, you shall be Sir Sonic, Knight of the Wind.
 * You shall see for yourself. Onward, my young Knave.
 * He is Knave the Hedgehog, and he accepts your challenge!
 * He is no knight. At least not yet.
 * That is Arondight one of the sacred swords of this land. Treat it with care.

Trivia

 * Caliburn's English voice actor, Casey Robertson, also voiced the first-level nightmaren, Reala from NiGHTS: Journey of Dreams.
 * Caliburn is what the real Excalibur was called before the name was altered by European authors, which is referenced as the missing Excalibur turns out to be Caliburn.
 * Sonic's finding of Caliburn references the way Arthur became King, which is probably because Sonic is technically King Arthur.
 * Caliburn's breaking in defense of Sonic echoes the sacrifice made by Shahra at the end of Sonic and the Secret Rings.
 * It may also be a reference to in the stories King Arthur gained Excalibur after his sword was cut in half during a battle.
 * After the second talk with Nimue, during which Sonic says that he's starting to get used to him, Caliburn says "That is exactly what I told you NOT to do!" as if he didn't want Sonic to get attached to him, probably because he knows that Sonic must return to his own universe.
 * In cutscenes, the ornament that attaches the middle of the hilt to the blade slides down and is replaced by Caliburn's face.
 * Caliburn is the only character in Sonic and the Black Knight whose mouth moves when speaking in non-3D cutscenes.
 * As Excalibur, Caliburn is the only inorganic, non-mechanical character to have a transformation.
 * Outside the Sonic series, Caliburn appears as the weapon for the Sonic skin used by the Felynes in Capcom's Monster Hunter 4 Ultimate.