Who is Daniel and Charles from Violets Are Blue and what is their importance?

Daniel and Charles are brothers and illusionists. They travel around the country performing what Hughes describes as an impressive illusionist show. When William and Michael attend their show in Las Vegas, they leave with the celebrity couple whom they later kill. While recuperating from his vampire bite, Cross connects the locations of the murders to the magicians' shows. The authorities quickly come to believe that Daniel and Charles are the killers they're looking for. Cross and Hughes infiltrate Daniel and Charles's home in New Orleans by attending an elaborate fetish ball that the brothers host. Daniel introduces himself as the Sire, or leader of the vampires. During a power outage, however, someone kills the two brothers. Cross then realizes that the murders are about a power struggle within the vampire society.