Second Exorcist Program

Background
The Second Exorcists is the name given to artficial exorcists created through the Second Exorcist program, which took place around two decades before the start of the events in D. Gray Man. The program was an attempt to create human beings who could join with the Innocence. It is not made clear what was done to prepare these artificial to bond with the Innocence but a powerful regeneration ability was included in their making so they could recover and survive from the stresses caused by the innocence during the bonding process.

The Program created Yu Kanda and his friend Alma Karma, the former seeming to be the first of the subjects to awaken. Others were shown in their own pools awaiting to awaken but it is currently unknown what happened to them. As of the present events in D. Gray Man, Yu Kanda is an Exorcist serving in the Black Order and Alma Karma is the 'womb' of the third Exorists, allowing regular humans to fuse with Akuma cells to become hybrids; half human, half akuma.

In the recent chapters, the history of the second exorcist program is revealed. It was a joint operation betweent the Epstein Family of the american branch and the Chan family of the Asian Branch. The two families pooled their resources to create the program, which would make exorcists to bond with the innocence since finding innocence hosts was quite time consuming and slow compared to the Millennium Earl's speedy production of Akuma. The humans created in the program were then bought before innocence fragments and then forced to bond with the innocence, an incredibly painful process that caused massive injuries to the created humans, which their deaths were only prevented due to a regeneration ability added in their make-up.

As of the present events of D. Gray Man, the second exorcist program has been cancelled. What happened to bring this about is unclear but a tragedy is hinted at and it seems to involve Yu and Alma Karma and the latter being killed at the hands of the former.....

Current Events
Currently the D. Gray Man Manga is revealing the history of the second exorcist program. The Earl and the Noahs Wisely, Tyki, Sheryill and Road (in the form of a doll) have attacked the american headquarters, where the third exorcist program and their womb, Alma Karma, is located, with a small army of level four akuma and have taken many of the senior members of the Black Order hierarchy and the science department hostage and have tricked Yu Kanda and Allen Walker into coming to the american HQ. The Noahs have two things in mind; they will force Allen Walker to expel himself from the Black Order by showing him the Black Order's past, and they will use the 'monster', hinted at being either Yu Kanda or Alma Kanda by awakening their memories, due to Wisely's mind powers. It is through the flashbacks that the history is being revealed.

Members

 * Yu Kanda is, of currently in the present circumstances of the D. Gray Man manga, the only 'active' Second Exorcist and the only Second Exorcist to successfully bond with an Innocence fragment - Mugen.
 * Alma Karma is currently the 'womb' of the Third Exorcists program, the reason being it was noted that ordinary humans could not survive and contain the Akuma cells. It is Alma's regeneration abilities that allow him to play such role.

Trivia

 * It is perhaps the first cross branch experiment to occur in the Black Order, or at least that is what is currently known. The Third Exorcist program would follow in it's wake.
 * The regeneration ability that second exorcists possess is a secret skill created by the Chang clan
 * It's been shown that the second exorcist are actually reincarnation's of dead exorcist's.
 * it was Alma Karma who annihilated rest of the 'sleeping' second exorcists, scientists and members of CROW
 * There is a theory among the fans that second exorcists are neither male nor female - that explains, for example, "a little feminine" look of Yu Kanda