The range on Thorn compared to Hawkmoon or Ace of spades seems lacking and the the fact that both them dont have a non cohesive mechanic for their buff to activate. Maybe removing the soul mechanic and replacing it with an actual curse like, "by holding your reload user will get cursed. While cursed, player takes more slightly more damage from enemies in return the burn is more effective for multiple hits on a cursed target." Think like Malfesence.