Evangelist was created by Blackheart by using his H'elian's Mirror Cauldron which creates inverted reflections of whomever stands before it. As Venom's antithesis he brings forth Flash's weakness's though his true definition has yet to be revealed.
Evangelist was created by Rick Remender and artist Tony Moore and debuted in Venom's Circle of Four miniseries.
Major Story Arcs
Venom - Circle of Four
Evangelist attacks Venom with pages from his Bible which fly out towards Flash. They pages separate Flash from the symbiote as Evangelist begins to verbally attack all of Flash's weakness's such as his dependency on the symbiote and alcohol and his issues with his father. Flash is left curled up on the floor unable to move.