Zadkiel (Daemon Prince)
The Blood Angels Librarian Mephiston believes Zadkiel to be a particularly dangerous Daemon, intended to become the herald of a new Tzeentchian empire in the Materium. Mephiston sees the Daemon as an immense threat should his plans be allowed to succeed, and now hunts him across the Galaxy.
Zadkiel has been summoned to Prospero by Magnus and manipulated the Thousand Sons Magister Lyræ to his own ends.[1a] He intended to summon Silver Towers on Terra to accelerate mutation and enhance the growth of Psykers on Humanity's throneworld.[1b] However due to the efforts of Mephiston Zadkiel bungled the summoning ritual, sending the Silver Towers back into the Labyrinth of Tzeentch. In a rage, Magnus banished him to the Warp for an eternity of torment.[1c]