Brother Jeremiah was a Shadowhunter and one of the Silent Brothers. He was relatively young, though his appearance was deformed due to the powerful runes placed on his skin as a Silent Brother.
The Mortal Instruments
City of Bones
Brother Jeremiah is called upon by Hodge Starkweather to assist them in retrieving Clary's seemingly lost memories. Stating that he cannot break the block set on her mind alone, he took her to the Silent City. When it is discovered that Magnus Bane had put the block on Clary's mind, Brother Jeremiah led Clary out of the Silent City.
City of Ashes
Wanting to steal the Mortal Sword kept in the Silent City, Valentine Morgenstern sent Agramon, the Demon of Fear, to them. Brother Jeremiah was among the casualties and was scared to death by the Greater Demon.
Just before his death, Brother Jeremiah managed to make his way to the holding cell where Jace Herondale was held for the evening. He dropped to the floor and died in front of Jace's cell, minutes after the screams began upstairs.
Physical description
Brother Jeremiah had pale white skin, littered with runes, some of them the most powerful runes in the Gray Book. His head was shaved and was said to look like an egg. He had no eyes, just indentations where they should be. His mouth was sewn shut, due to the fact that he no longer needed to speak, thanks to the powerful runes placed on him as a Silent Brother.
He was described to have smelled like "spices".
Abilities
Brother Jeremiah possessed an array of powers.
- Telepathy - Brother Jeremiah possessed the ability to read the minds of those around him.
- Runes - As a Shadowhunter, Brother Jeremiah possessed the ability to bear the marks of the angels which granted him superior strength and many other abilities.
Paraphernalia
Stele - Brother Jeremiah, like any other Shadowhunter, also possessed a Stele, which he used to draw runes.