The Sinister Minister debuted in World Championship Wrestling (WCW) in 1997 as James Vandenberg, the manager of Mortis, a masked wrestler billed as a shoot fighter from Taipei who was one of Vandenberg's "rare oddities". Mortis feuded with Glacier in an angle titled "Blood Runs Cold," and faced him at Uncensored on March 16, 1997 in his pay-per-view debut, which he lost. Following the match, Wrath debuted, siding with Mortis and Vandenberg, and attacking Glacier. Glacier defeated Mortis in a rematch at Slamboree on May 18, when Wrath interfered on Mortis' behalf, causing a disqualification; Glacier then suffered another post-match beating before Ernest "The Cat" Miller ran to the ring to defend him. The four men fought one another over the following weeks, culminating in a match at Bash at the Beach on July 13, which was won by Mortis and Wrath. After Blood Runs Cold officially ended, Vandenberg continued to manage the pair through the remainder of 1997 as Mortis and Wrath entered a feud with The Faces of Fear that culminated in a pinfall victory at Fall Brawl. In early 1998, the group was split up after Wrath was sidelined with an injury and Mortis was moved into a new angle involving Raven and the Flock.
Vandenberg then tried to get a commentary segment off the ground on WCW Saturday Night, titled Vandenberg's Odditorium. He appeared on camera standing alone in a dimly-lit space, discussing current feuds such as that between Saturn and Glacier, always finishing the segment with "And I could be wrong...but I doubt it." The segment was quietly axed after a few weeks. Vandenberg was then released from WCW.
In 2000, he debuted in Extreme Championship Wrestling (ECW) as an unnamed evil priest character. He was originally planned to manage Mike Awesome, but instead began an angle with Raven. The angle was dropped when Raven left ECW, and he was subsequently rebranded as The Sinister Minister, a heel narrator for ECW on TNN. Upon debuting as a manager, he was surprisingly accepted as a fan favorite by the crowd. He managed The Unholy Alliance (Yoshihiro Tajiri and Mikey Whipwreck) during their feud with The Full Blooded Italians.
The Sinister Minister appeared at the World Wrestling Entertainment-produced ECW reunion pay-per-view ECW One Night Stand on June 12, 2005. He and Mikey Whipwreck accompanied Tajiri to ringside for his match with Super Crazy and Little Guido.