In adventure mode,pick a destination,then,when it goes to the section where it says pick a character(it doesn't matter if you have beaten knight's passage or not),press the following 7 commands with the nunchuck and the d-pad(the directional pad):C,Z,UP,UP,DOWN,RIGHT,C,then,go to past the last character and it will show Excalibur sonic with Excalibur in the character slot,choose him with the A button,then, pick a mission,then,once you are doing the mission,you will have Excalibur Sonic along with Excalibur.