Bjorn's saga of greatness would begin in earnest during the Burning of Prospero. The exact account of what happened on Prospero has been lost to time, but it is known that some thing, whether foul Warlock of the Thousand Sons or Neverborn abomination had taken a special interest in Kasper Hawser, ostensibly attempting to use the mortal as a spy against the Vlyka Fenryka, but in truth to ensure that the confrontation between the Space Wolves and Thousand Sons resulted in their mutual annihilation. The being revealed itself to its unwilling mortal pawn on Prospero, and when Hawser defiantly planted his axe into the foul creature's head, the monster started to choke the life out of him due to its inveterate malice. Bjorn intervened, hacking the foul being's arm off at the elbow and saving Haw