The Babylon Guardian (called Angelus the Gatekeeper in Japan) is the final boss of Sonic Riders. He is a genie-like being originating from the ancient Babylonians and the guardian God of Babylon Garden, who is tasked with safeguarding the Treasure of Babylon from within the floating city's phantasmal core. The Babylon Garden and his nature is somewhat enigmatic. However, the digital distortions occurring in the Babylon Guardian's domain whenever he is injured implie that he is actually a solidified holographic security system created by the Babylonians' technology.