Horphis is a visitor in Great Kourend's Arceuus House Library. He seeks dark manuscripts within the library, and will ask the player to retrieve them once they have at least 20% favour with the Arceuus House. He will give players a book of arcane knowledge for each manuscript turned in, in addition to 5% favour.
Horphis is the solution to the medium anagram clue: HIS PHOR. The answer to his challenge scroll is 1.