Unlike most of Sonic's other normal transformations, Sonic himself does not undergo any physical change. Instead, he dons a shining golden armor with silver accents. This armor covers his entire body (except for his tail) and is highly detailed. Noticeably, his feet armor resemble Sonic's shoes, but with upturned and pointy toes, and sharp cuffs on each side. He also gets sharp kneepads, pelvis plates, small shoulder guards, and wrist cuffs with a sharp end on each of them and a red gem embedded in them. His helmet possesses a visor with silver accents, a red gem on the forehead and wing-like ornaments on the visor joints. The armor also covers Sonic's quills and are flexible due to their multiple plates. Lastly, the armor is decorated with medival lines in various places, and a red cape runs down the back of the armor.
Sonic and the Black Knight
In Sonic and the Black Knight. when Sonic proclaimed his intend to defeat the Dark Queen despite having Caliburn cut in half and being outmatched against the dark wizard, his resolve awoke the long-lost light of the sacred sword. The Knights of the Round Table proceeded to send their sacred swords to Sonic, and together, their power transformed Sonic into Excalibur Sonic and restored Caliburn as his ultimate form: Excalibur. Together, Excalibur Sonic engaged the Dark Queen with Excalibur in hand. In response, the Dark Queen assumed a giant spectral form of the late King Arthur. However, even that was not enough to stop Excalibur Sonic, who ended the fight by piercing the Dark Queen's spectral form with Excalibur. WIth the Dark Queen reverted back to Merlina, Excalibur Sonic let his form go as well.
In this game, Excalibur Sonic is only playable during the "Defeat the Boss: The Dark Queen" Mission in Dark Hollow. When beginning the fight, Excalibur Sonic will have one hundred Rings in his possession. However, the player cannot pick up Rings throughout the Mission. In exchange, Sonic can maintain this form without sustainment from the Rings in his possession, and his Ring count will not be decreasing over time like Super Sonic's.
In gameplay, Excalibur Sonic takes damage like he would normally during any other Mission, meaning that the player will lose Rings each time Excalibur Sonic takes a hit. If Excalibur Sonic takes a hit without any Rings on him, the player will have to start the Mission over. In return, Excalibur Sonic will only lose twenty Rings for each instance of damage. Also, he can perform dodges by rolling to the left or right when pressing or respectively. In addition, while Excalibur Sonic can perform sword slashes by swinging the Wii Remote, the only attack in his arsenal that can damage the Dark Queen is Excalibur Sonic's Soul Surge, which can be charged up by countering the Dark Queen's sword trikes.
In this form, Sonic is renowned as the ultimate Knight, hinting a high level of skill and power. He has increased strength, allowing him to deflect the massive sword strikes from the Dark Queen's spectral form with ease, and the ability to fly at high speed. In addition, Sonic retains his skills in swordsmanship, allowing him to parry the crushing sword strikes from the Dark Queen and deflect projectiles with just Excalibur. He also gains increased acrobatic skills and reflexes that enables him to make spinning rolls in midair to avoid attacks. Lastly, he can channel a form of magical golden energy into Excalibur that greatly increases the devastating power behind his sword thrusts.
As Excalibur Sonic, Sonic wields Caliburn in his legendary form, Excalibur, the greatest of all the sacred swords. With it, Excalibur Sonic can cut through anything, including magical barriers, and deflect magical energy projectiles. He can also use Excalibur for his most powerful attack where he thrusts Excalibur directly through his opponent while enveloped in a golden energy meteor.
↑Sega (November 13, 2011). Mario & Sonic at the London 2012 Olympic Games. Nintendo Wii. Sega. Area: London Party. "Shy Guy: Sonic the Werehog wears a golden suit of armor and a helmet, right? [...] That's Excalibur Sonic!"