Generator Rex was a Cartoon Network animated series about a teenager who can generate machines from his body, and the Black Knight was one of its later antagonists, a calculating leader whose presence signalled a darker turn in the story. The theme circulated among fans as part of the show's soundtrack, shared as a standalone track for edits and soundboards. Because the music is instantly associated with a cold, authoritative villain, creators still reuse it, like other character themes, years after the series ended to give fan videos, AMVs, and gaming clips the same sense of impending threat.