Deacon Blackfire

Deacon Joseph Blackfire is a sinister preacher and a villain in the DC comics.

The Cult
Deacon Blackfire is a conman and cult leader who was over 100 years old at the time of his death, despite appearing much younger. He has discovered the secret to eternal youth, bathing in buckets and buckets of human blood. Blackfire craves power and destruction, and orchestrates his movements toward these goals. During The Cult he forms an army in the sewers beneath Gotham City, largely composed of the homeless and derelict. Blackfire uses this army to begin a violent war on crime, which escalates into him taking over the entire city, resulting in it being isolated from the rest of the country. Blackfire captures and brainwashes Batman, temporarily making the Caped Crusader a member of Blackfire's cult. Batman eventually breaks his conditioning, but its after-effects make it difficult for him to capture Blackfire. After a brutal search through the sewers with Robin, Batman confronts Blackfire, who demands that Batman kill him, making him a martyr. Batman refuses, and instead savagely beats Blackfire in front of his army. Blackfire's army turns on him and kills him.

Blackest Night
Deacon Blackfire is one of the many villains raised from the dead in Gotham City to join the new Black Lantern Corps as zombies during Blackest Night. Along with Abbatoir, KGBeast, Blockbuster, King Snake, Magpie, the Trigger Twins, and the Ventriloquist, he has received a Black Lantern Ring. He has been seen terrorizing the city, and tearing out the hearts of innocents in churches to feed on their emotions and life force when they're feeling the most compassion.

Batman: Arkham Knight
Deacon Blackfire appears in Batman: Arkham Knight in a side quest riling up his cult to start Armageddon in Gotham and getting ready to sacrifice Jack Ryder, only to be stopped by Batman.

Trivia

 * He is no relation to Blackfire of the Teen Titans.