The story of "Demon Knights" is set in the Dark Ages, specifically within the medieval period of the DC Universe's history. This setting provides a unique backdrop for the comic, distinguishing it from other more modern or futuristic titles within the DC Comics lineup. You can find more information on Wikipedia or TV Tropes.
Here are a few images related to the comic:
In what year did Demon Kakka start using the stage name Demon Kogure Kakka?
Who are the main characters featured in Demon Knights?
How did Demon Kakka start his music career with Seikima-II?
Which game from 1993 includes Demon Kakka as a notable character?
What are some of the musical releases in Demon Kakka's solo career?