Randolph Carter

A man named Randolph. Back when he was still human he was praised as the first of the peerless Scholars. He'd been insane for a long time, even before the City warped. He desires the truth. The truth of the City? Why the City turned into this? No, that's not it. He desires that which is truth to him.
(Edited from in-game text)

Spoiler

7th of the 10 Peerless Scholars: The Grand Librarian (《大司書》), he was part of the very first expedition that led to the discover of planet Kadath along with Laura Nadelmann (the Expedition Princess) and Charles Babbage (the Steam King)