Inarius, a renegade Angel and the creator of Sanctuary, wanted its inhabitants to worship him and fuel his ego, although he appears to be the only known Angel to desire this. While some are sympathetic to humans and truly believe in their potential for good, such as Auriel, freely offer advice and guidance to them even the bowels of Hell itself, such as Hadriel, and even go as far as continually aiding them in their struggles with the Evils and their many mortal and demonic servants, such as Tyrael, the forces of Heaven have thus far largely ceased to interact with Sanctuary and with humanity or interfere with the affairs of mortals, allowing each to choose their own path, for good or ill.
Even so, in battle, Angels can strike as much fear in mortal hearts as demons. They wield the elemental powers of Ice and Lightning and Light, and are expert melee fighters. The Seraphim division of the Angelic Army has been known to sweep entire legions of Demons in a single day. All angels have the power to fly, excluding Fallen Angels. A fallen angel is an angel that has been exiled or banished from the High Heavens. This can come to be because of corruption, or more often such banishment is a punishment for disobeying or rebelling against the Angiris Council. Another way is for deliberate betrayal by an angel.
Izual was a great lieutenant and friend to the Archangel Tyrael. He once led a fierce attack upon the Hellforge as the creation of the dark demonblade Shadowfang was nearing completion. During the battle that ensued, Izual was overcome by legions of Chaos and was lost to the Darkness. His body was corrupted by the Prime Evils as they forced his soul into the body of a demon, turning him into a demonic monstrosity. They forced him to betray his own kind and give up Heaven’s most guarded secrets. Izual became a corrupt shadow of his former self; a fallen angel trusted neither by Heaven nor Hell.