Diablo/The Butcher

Defeating the Butcher requires either a higher level warrior (around level 9) with decent equipment, or any character with the spell "Fire Wall". Simply defeat all of the surrounding enemies in the area and then quickly open the door to the butcher's room and cast a few Fire Wall spells right in the first square tile on the inside of the room and then immediately shut the door. After the flames die down, the butcher should be weakened or in the case of higher level fire walls, dead. Another strategy is to open the door to the butcher's room and then run into a room with a wall you can fire arrows through and shut the door. Since the butcher can't open doors in the dungeons you can mercilessly fire arrows at him until he is dead.