Merlin (マーリン,Mārin?) is a character mentioned in Sonic and the Black Knight. He was a legendary wizard from the world of Camelot and the grandfather of Merlina the Wizard. Merlin was the one who created King Arthur and lead him to become king of England to bring peace and a just rule to the kingdom. However, Arthur eventually turned evil and began enslaving the kingdom, making the fallen King, as Merlina describes him, Merlin's greatest mistake.
Years prior to the events of Sonic and the Black Knight, Merlin used his trickery to have King Uther Pendragon and Lady Igraine, the queen to an enemy country, conceive Arthur, a magical illusion created from the forces of the underworld. Just after Arthur was born, Merlin went against the King's wishes and took Arthur away. Merlin then gave the infant Arthur to Sir Ector to be raised.
At some point, Merlin placed the sacred swordCaliburn in a stone, claiming that only the true King of England would be able to pull it out. Eventually, Arthur pulled out Caliburn and became the ruler of England, fulfilling the destiny Merlin had prepared for him. During Arthur's noble rule, Merlin guided Arthur to a lake in the Deep Woods when the King broke his own sword, intending to have Arthur claim Excalibur to replace it.
Merlin's current status and fate are unknown, as any information at this point goes unaddressed, though as implied by Merlina, he has most likely passed away.
Real world background
Merlin is a legendary figure, most famous as a wizard and the advisor of King Arthur. The standard depiction of the character first appears in Geoffrey of Monmouth's Historia Regum Britanniae, written c. 1136, and is based on an amalgamation of previous historical and legendary figures, including Myrddin Wyllt (a madman and bard from the north of Britain) and Ambrosius Aurelianus (a Roman war leader).
The stories involving Merlin are many and varied, having been retold and re-interpreted many times over the last nine hundred years. Stories involving Merlin typically include that he was fathered by a demon, thus explaining the origin of his magic powers, that he helped build Stonehenge, and that he used his magic to help Uther Pendragon to father a son (later King Arthur) on his enemy's wife, Igraine. Merlin is also described as tutoring the young Arthur and advising him once he becomes King, and of placing the Sword in the Stone to prove Arthur's right to rule.
Merlin is usually depicted as disappearing during King Arthur's rule, having fallen in love with a woman named Nimue, Niniane, Niviane, or Viviane (depending on the version of the legend). Nimue (sometimes considered also to be the Lady of the Lake, as in Sonic and the Black Knight) traps Merlin in a tree, cave, tomb or tower with his own magic.
↑Sonic Team (March 13, 2009). Sonic and the Black Knight. Nintendo Wii. Gallery. Vault 5. [Birth of Arthur] "Born to King Uther Pendragon and Lady Igraine, an enemy country's queen, with the help of Merlin's trickery. Against the King's wishes, Merlin took the newborn Arthur away and gave him to Sir Ector to raise."
↑Sonic Team (March 13, 2009). Sonic and the Black Knight. Nintendo Wii. Gallery. Vault 5. [Legendary Sword] "Merlin placed the sword in the stone claiming that none but the true King could pull it out. None were able to pull the sword free except Arthur. That act made him the King of all England."
↑Sonic Team (March 13, 2009). Sonic and the Black Knight. Nintendo Wii. Gallery. Vault 5. [Excalibur] "When Arthur broke his sword, Merlin guided him to the lake where he found a sword held aloft by fairy magic. Arthur went out in a small boat and claimed the sword. That sword was the legendary Excalibur, which Arthur used to save the kingdom countless times."