Elphas the Unsteady is an ancient warlock and the first Downworlder that Jonathan Shadowhunter directly interacted with. His friendship with Jonathan Shadowhunter set a precedent that lasted more than four hundred years. He is said to be the brother of Baba Agnieszka.
Elphas wrote the earliest known "Nephilim-approved" demonology, compiling data from his and the first-generation Shadowhunters' personal experiences and offering extensive commentary on other earlier demonologies, since new Shadowhunters often would possess some "foreknowledge of Downworld" that turned out to be entirely false and based on popular, incorrect texts.
- The Shadowhunter's Codex (first and only mention)