Azrael is the name of the Jewish and Islamic angel of death and the fourth of the archangels. In the Batverse Azrael is the Avenging Angel of the Order of Saint Dumas, a highly secretive religious order that deals quickly and severely with any transgression.

The role of Azrael is passed down from father to son with the son being secretly being programmed with the system, this programming is kept secret from the child that will become Azrael. Jean Paul Valley's first appearance in Sword of Azrael #1 shows him being unexpectedly being visited by his dying father who tells him that he must now take over as Azrael.

"Know that men call you Liar!
Know that men call you Betrayer!
Know that men call you Defiler!
Therefore, it is the duty of the Angel Azrael to bring you-- Punishment--
The Punishment of Death by Fiery Sword!" Azrael, Sword of Azrael #1

When Batman and Azrael first met it led to the traditional fight that happens the first time any two heroes meet, but it quickly became clear that Az was not going to follow orders like a good Azrael should. Jean Paul Valley may have been corrupted by all that time spent in Gotham City but after saving Batman from a burning oil plant at the end of Sword of Azrael Bats decided that he should receive his kind of training rather than the Order's idea of training. Bruce got him a job as a security guard at Wayne Tech and made Robin responsible for Azrael's training.

When Bane carried out his plan to destroy Batman in Knightfall, Bruce realised that there must still be a Batman but rather than ask Dick to put on the Suit, the story demanded that Azrael be given the suit.

When Az was given the Mantle of the Bat Bruce told him not to go after Bane... so obviously he had to go after him but not without giving himself an advantage by improving the Bat suits weaponry.

Tim Drake: "It's bad out there, Bruce... Real bad.. and I've been thinking..."
Bruce: "You've been thinking someone should... fill in... and I agree."
Tim: "You do? Then you are in a better mood... I guess. Should I go to Nightwing."
Bruce: "No... he's his own man now... with his own responsibilities..."
Tim: "Then the only other possibility..."
Bruce: "Yes... but I want it made clear... absolutely clear that under no circumstances does he confront -- BANE!" Batman #498, Knightfall Part 15

Azrael was initially created to be hated: Dennis O'Neil stated that we weren't meant to like Azrael and that he wouldn't have known what to do if the readers had liked him. I'll be amazed if the Batman editors didn't have an agenda when they were developing the idea behind Knightfall. Denny has talked about the amount of violence that was conducted by the heroes in films but I can't help wondering if the success of Image Comics the real motivation behind . Whatever the motivation the point of the story was always to find out what kind of hero people wanted; did people want a hero who would be every bit as violent as the villain. If the hero is as violent as the villain it becomes increasingly difficult to tell who is the villain all we can say is that this character is the focus of the comic.

Everyone must have known that eventually Bruce would come back to be Batman so the success of the story depends upon how it is told. KnightQuest, the central part of the Knightfall saga, is unsurprisingly thought to be the weakest part of the tale; AzBat continued on his Crusade against crime in Gotham while Bruce went on a Search to find his doctor and Tim Drake's father.

As the story progressed The System affected AzBat more and more leading to the costume becoming a suit of armour that fired shurikens before Az added a flame thrower, and a level of violence that meant when Bruce found out what had happened he would have to take back the Mantle of the Bat. The final straw was when Az let Abattoir die without finding out what Abattoir had done with the cousin that he had kidnapped. Abattoir's cousin consequently died.

Bruce defeated Azrael in Knightsend by using his wits rather than brute strength and decided to let Jean Paul go rather than hand him over to the police. Azrael's story has always been the conflict between Jean Paul Valley, a computer student, and The System, the programming that all Azrael's receive. This was the main theme of Knightfall for Azrael and it continues throughout the ongoing series. When Jean Paul puts the mask on he becomes Azrael with predictable consequences and lack of control; Azrael has all the knowledge provided by the system.

There have been attempts to reduce the influence of The System; after being framed for murder Jean Paul had to lose the familiar Azrael suit and put on a new outfit, which doesn't cause The System to be brought into effect.

Batman is so unbelievably good at so many things that clearly something had to give, hence the fact that he has so much trouble understanding his and others emotions; he can control the important ones in combat but otherwise he's a mess. Not only did he not realise that Dick was the only one to ask to fill in during Knightfall, he didn't realise that Jean Paul was nowhere near being ready for such responsibility and that absolutely the last thing at the end of Knightfall was to do was to send Jean Paul off on his own.

The realisation of these mistakes has been instrumental in turning Batman from an obsessed individual into more of a team player by making Azrael very much a member of the family, even changing the title of his comic to Azrael: Agent of the Bat. This was quickly followed by a new, but not nearly as good looking, costume necessitated by him being accused of killing a senator. The System is also less likely to affect Jean Paul when he is wearing his new costume.