Kalarel the Vile                                            At will: detect magic, magic missile
1st level (4 slots): ray of sickness, sleep, mage armor
   Medium Humanoid, lawful evil
                                                               2nd level (3 slots): hold person, mirror image, arms of
   Armor Class 13 (16 with mage armor)                         hadar
   Hit Points 97 (15d8 + 30)                                   3rd level (3 slots): animate dead, bestow curse,
   Speed 30ft.                                                 counterspell, vampiric touch
                                                               4th level (3 slots): banishment, phantasmal killer
                                                               5th level (2 slots): contact other plane, hallow
      STR       DEX      CON        INT        WIS       CHA
    14 (+2) 16 (+3) 15 (+2) 16 (+3) 18 (+4) 17 (+3)
                                                               Actions
                                                               Rod of Ruin. Melee Weapon Attack: +5 to hit, reach 5ft.,
   Skills Deception +6, Religion +6, Perception +7,            one target. Hit 9 (1d8 + 4) bludgeoning damage plus 7
   Senses passive Perception 17                                (2d6) necrotic damage
   Languages Common, Abyssal                                   Raise Servant (Recharge 5-6). An unconscious adversary
   Challenge 8 (3,900 XP)                                      rolls 1d20, on a 10 or lower, Kalarel takes control of
                                                               the creature and turns them into an undead monster of
   Spellcasting. Kalarel the Vile's spellcasting ability is    the Dungeon Master's choosing, or roll on the
   Wisdom (spell save DC 15, +7 to hit with spell              following table. Otherwise the target automatically fails
   attacks). He has the following spells prepared:             one death saving throw.
        d100            Undead Type
         1-30           Zombie
        31-50           Ghast
        51-65           Wight
        66-80           Wraith
        81-95           Revenant
       96-100           Vampire
  Notes: Kalarel might use hallow to give all enemies in his
chambers vulnerability to necrotic damage, which he can
exploit through vampiric touch, and arms of hadar.