Na-Krul was banished to the Void by Diablo. However, during the Darkening of Tristram, he was freed by a Dark Mage. The mage was able to hinder the demon through arcane magic and encase it within walls, but feared that the demon would be too powerful to defeat unless the grimoires he left behind were used. The mage later perished.
Na-Krul is the boss of Diablo: Hellfire. He is similar to Diablo in strength, but the fight is slightly easier as he lacks the hordes of enemies that accompany Diablo in his correspondent boss fight. He also lacks any magical attacks, but moves and attacks quickly. Prior to the fight, the player can weaken Na-Krul beforehand by reading three spellbooks in front of his room. Releasing Na-Krul through this method cuts his Life in half, and reduces his armor rating by nearly as much. The correct order is as follows:
- In Spiritu Sanctum.
- Praedictum Otium.
- Efficio Obitus Ut Inimicus.
Alternatively, a player can free Na-Krul simply by using a lever.
- "What? Who dares disturb the great Na-Krul? Your life is forfeit, mortal!" (if the player used the spellbooks)
- "Out of my way, human! Retribution calls for he whom you call Diablo!" (if the player used the lever)
- *laughs* "Free! *laughs* Free to confront the one who banished me to the void, Diablo! And free to reward you, little mortal, with your death!" (unused)
- "Accept your death, worm. The rest of your kind will follow you soon enough." (unused)
- "When you get to hell, maggot, tell them that I'm coming to rule!" (unused)
- "Hi! I'm free, free to confront the little man who banished me, Diablo. Hi, everybody, and I'm free to reward you, little mortal, with these Aerosmith tickets. You'll be getting backstage passes, you'll get to meet Steven Tyler and the whole band. This Friday at the Coliseum. Thanks for getting me out of there. By the way, I'm gonna have to kill you. (pause) I'll be right back with the traffic and weather together." (if a player enters a Command.txt exploit)