- Voiced by: Takehito Koyasu (Japanese), Troy Baker (English)
- The Holy Sword, as a legendary weapon that is unmatched by any other. Although he is considered the most powerful weapon in the world, he can be used by anyone. Unfortunately, upon finding him, most are unable to stand being around him for a long period of time. This is especially true when those who had previously encountered him show a look of absolute disdain at his mere presence. He has a large ego, ignores others while they attempt to speak by calling them "fools", and he goes on long, nonsensical rants. He demands that his meister perform one thousand tasks, such as a daily five-hour reading of his own book. His humanoid form resembles a cartoon-ish anthropomorphic creature with a very long snout, dressed in a white suit and top hat. Hero (Voiced by:Hiro Shimono (Japanese), Z Charles Bolton (English)), a loser student who would be considered popular at any other school, manages to satisfy Excalibur's demands for a time (due to already being used to being everyone's whipping boy), which grants him instant teleportation, flight using large wings of light, and power attacks that cause explosions. Using these skills allowed him to defeat Black Star, Kilik, and Kid in a 3-on-1 duel. This miraculous partnership soon ended when Hero was unable to tolerate Excalibur's sneezing fits. While not with a meister, Excalibur spends his time in a rock in the middle of a shallow lake inside a cavern on top of a cliff, which annoys the fairies that inhabit the area.