Delan Araqiel was a successful Interrogator-Chaplain from the ranks of the Dark Angels. Having trained under the eye of Master of Sanctity Sapphon and the Interrogator-Chaplain known to the Chapter as High Interrogator Asmodai, Delan possesses five black pearls on his Rosarius as an indication of how many Fallen he has made repent.
Thanks to his abilities as an Interrogator, Araqiel's methods are notable in that he would calmly list the many atrocities that the Fallen would soon be subject to if they would not repent - while he would never go back on his promise of giving them a quick death, despite his forewarnings, his Fallen captives often pressed their luck and he has inflicted considerable agony upon them before they broke and repented.
However, it was clear that his time doing this questionable duty that Araqiel slowly fell into the grips of madness, driven insane by the truth of the Fallen. As he became more and more disillusioned with his Chapter, he suffered visions and whispers from a Fallen Librarian by the name of Nefar Valac, who had taken up refuge in an Emperor's Children warband called the Thrall of Concordius, lead by the eponymous Chaos Lord, slowly turning to Chaos during the Reclamation of Foeturn. Once he actively turned on his brothers, he was challenged to combat by the Third Company's Champion, an old friend. He was soon slain afterwards.
Araqiel, as Chaplain, is heavily spiritual and dedicates much of his time to prayer and veneration. A big thinker yet a man of action, Delan's ability to inspire his men was inherited from Sapphon, and as a result can easily push his men into fighting on. Araqiel was, like a few of his other brothers, opposed to some of the Imperial Ecclesiarchy's views, such as the virtue of hate distracting the mind and clouding the thoughts. As a result, especially in combat situations, Delan possesses an eerie calm about himself that unnerves even his brothers. However, when the time called for it, he would raise his Crozius to the air and call for the heretics to be burned at the top of his superhuman lungs.