Deacon Joseph Blackfire is a religious leader who has been believed to have already lived a century long. He is a Native American shaman who was entombed alive for killing a tribal chief and committing heresy. Blackfire's body was found sometime later (days) by the Dutchmen. The people who found him began to mysteriously disappear. Only a few were left when one witness said; 'A naked man was walking away from the area.'
Major Story Arcs
Batman: The Cult
Years afterward, Blackfire formed a group of followers. He amassed an army consisting of Gotham City's homeless and including a few people reported missing. Using the city sewers as their home and base of operations, Joseph Blackfire led the army to a rebellion against crime, being a religious leader as he was. This mission would conclude with taking over Gotham City as the ultimate means to rid the City of it's criminal influence. An influence that was heavily ingrained.
Blackfire was able to capture Batman, the Dark Knight and brainwashed him with a drug. Thus, he became one of Blackfire's lackeys. However, soon Batman was able to overcome the brainwash condition. He found himself being updated by Robin (Jason Todd), and goes on the hunt for Blackfire. However, the drug used in his brainwashing was tricky as it had severe after/side effects that made it difficult to track Joseph Blackfire.
The people of Gotham were in total panic when Blackfire's army attempted to take over Gotham. The citizens who refused to join were gunned down by the homeless, brainwashed troops. The National Guard, capable soldiers, went down to the sewers and were slaughtered. The Governor asked for federal aid and declared Gotham City a disaster area. He decided to tell all remaining citizens to leave the city.
The media even showed videos of people being killed by executioners like the Middle Ages. After searching the whole sewers, Robin (Jason Todd) was shot. Batman confronted Joseph Blackfire who was ready to die. He even begged Batman to kill him in order to turn himself into a martyr symbol for his followers. After Batman gave him the beating of his life, however, the homeless army turned on Blackfire and killed him. As Batman left, he lit Blackfire’s totem on fire and the entire city began healing, putting an end to the nightmare.
For more information see: Blackest Night
During the Blackest Night, Deacon Blackfire's body was raised by a black power ring and became a Black Lantern. Along with the other Batman villains brought back from the dead, Blackfire attacked the Gotham City Police Headquarters.
While in Arkham Asylum, Doctor Phosphorus hears voices and is then attacked by the glowing ghost of a priest who looks like Blackfire. When the ghost orders the Phosphorus to say his name, he says "Blackfire" and explodes.