|“||I am an angel of the divine. I am brother to the Sijil, Kurabi, and the Zurah, the Fravashis and Dakinis.||”|
Bound to Tessa
- Main article: Clockwork angel (pendant)
Somehow, around the time of the Crusades, a part of Ithuriel's soul was trapped by John Shade through a spell and contained inside the clockwork angel, which he intended to give to his wife, Anne. His adopted son, Axel Mortmain, spent years finishing the pendant. He tuned it to Tessa Gray's life and gave it to her mother, Elizabeth, to someday pass onto her. The angel, connected to Tessa, was designed to protect her and save her from death. He made sure that Tessa, as a Shadowhunter and demon hybrid, was born alive instead of stillborn.
Some time after Elizabeth's death, Nate gave the seemingly defective clockwork pendant to Tessa, who has since worn it as a necklace. The necklace has saved Tessa from several near-death experiences.
When Tessa decided that she did not want the necklace protecting her because Mortmain willed it, Tessa tried to destroy it in a fire. While the clockwork remained unharmed, Ithuriel was summoned and spoke to her. Ithuriel told her that he never blamed her for his imprisonment. During the final battle, Tessa Changed into Ithuriel to protect her loved ones and to kill Mortmain. Changing into him momentarily enveloped Tessa in the angel's heavenly fire, nearly killing her. Ithuriel was then freed.
Imprisoned by Valentine
More than a hundred years after he was released from the necklace, Ithuriel was summoned by Valentine and trapped in the cellar of the Wayland manor house in Idris. Valentine tortured him for information about the Mortal Mirror, but Ithuriel remained silent.
Valentine took blood from him and administered it to an unknowing Céline Herondale through food and drinks while she was pregnant with Jace Herondale. This experiment ultimately gave Jace abilities that surpassed those of common Shadowhunters. He also gave it to Jocelyn the same way in order to cure her of her depression. However, Valentine was unaware that Jocelyn was also pregnant with Clary, which led to her being gifted with the ability to create runes known only to angels, through images and visions of them he sends her, as well as amplify the power of all existing Marks she makes.
Ithuriel remained imprisoned in this cellar for years. He began to send prophetic dreams to Clary Fray, in hopes that by giving her answers, she could help stop Valentine. The dreams included warning her of the fact that Simon Lewis would be turned into a vampire, about angels falling from Heaven, and showing her what Idris looked like so she would have a mental picture in which to create a Portal.
Death on Earth
While in Idris, Clary and Jace were exploring Wayland manor in search of the Book of the White. When they found it, they heard Ithuriel making noises in the cellar and found him bound in a circle of runes. Ithuriel showed them visions of Valentine's history. He also gave Clary a vision of the Alliance rune. Clary then changed the runes in the circle in which Ithuriel was bound. Realizing that there was no hope to cure him, Jace named his seraph blade Ithuriel and gave it to the angel, enabling him to kill himself, finally ending his torment on Earth, and return to Heaven. Since Wayland manor was tied to his life force, it began to crumble when he died.
Once he returned, he told the Angel Raziel of Valentine's cruel deeds. It was also through an image of a rune that Ithuriel had previously given Clary that she was able to contain heavenly fire in Heosphoros and finally defeat Sebastian Morgenstern.
Ithuriel was described as glorious, with curling blond hair and completely gold eyes, with wings that had eyes on the feathers. Some time before his "death", Ithuriel's eyes were taken out, most likely by Valentine.
- When Tessa Gray changed into Ithuriel, she was enveloped by the angel's heavenly fire and only survived because the angel protected her. Similarly, Jace Herondale was also enveloped by the heavenly fire when he was stabbed with Glorious, surviving with Ithuriel's blood in him, aided by the fact that there was more good than evil in him.
- Will, his male descendants, Jocelyn, and Clary all have white star-shaped scars because of him. Will got it by coming in contact with Tessa's clockwork angel, which held his spirit, and the mark was passed onto his male descendants. Jocelyn got hers because Valentine fed her powders of Ithuriel's blood while she had been carrying Clary, who was then born with Ithuriel's blood and the mark.