5e SRD >Creatures >

Seething Oblivion

Medium undead, neutral evil

Armor Class 15
Hit Points 246 (29d8 + 116)
Speed 0 ft., fly 60 ft. (hover)

STR DEX CON INT WIS CHA
7 (-2) 20 (+5) 19 (+4) 14 (+2) 15 (+2) 20 (+5)

Damage Vulnerabilities radiant

Damage Resistances acid, cold, fire, lightning, thunder; bludgeoning, piercing, and slashing damage from nonmagical attacks
Damage Immunities necrotic, poison
Condition Immunities charmed, exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses darkvision 60 ft., passive perception 12
Languages the languages it knew in life
Challenge 18 (20,000 XP)

Special Traits

  • Incorporeal Movement. The seething oblivion can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.
  • Legendary Resistance (3/Day). When the seething oblivion fails a saving throw, it can choose to succeed instead.
  • Specter Servants. The seething oblivion’s Life Drain and Create Specter abilities can both create specters under the seething oblivion’s control. The seething oblivion can have no more than 11 total specters under its control at a time.
  • Sunlight Sensitivity. While in sunlight, the seething oblivion has disadvantage on attack rolls, as well as Wisdom (Perception) checks that rely on sight.

Actions

  • Life Drain. Melee Weapon Attack: +11 to hit, reach 5 ft., one creature. Hit: 54 (12d8) necrotic damage, and the target must succeed on a DC 19 Constitution saving throw, or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the creature finishes a long rest. The target dies if this effect reduces its hit point maximum to 0. If a creature is slain by this attack, its spirit rises on the next turn as a deadly specter (p.138) in the space of its corpse, or in the nearest unoccupied space. The specter is under the seething oblivion’s control.
  • Necrotic Lash. Melee Weapon Attack: +11 to hit, reach 5 ft., one creature. Hit: 22 (5d8) necrotic damage.
  • Create Specter. The seething oblivion targets a corpse within 10 feet of it that has been dead for no longer than an hour, and died violently. The target’s spirit rises as a deadly specter in the space of its corpse, or in the nearest unoccupied space. The specter is under the seething oblivion’s control.

Legendary Actions

The seething oblivion can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature’s turn. The seething oblivion regains spent legendary actions at the start of its turn.

  • Shift. The seething oblivion flies up to half its fly speed, without provoking opportunity attacks.
  • Hateful Lash. The seething oblivion makes a Necrotic Lash attack.
  • Create Specter (Costs 2 Actions). The seething oblivion uses its Create Specter ability.
Section 15: Copyright Notice

Ultimate Bestiary: The Dreaded Accursed, Copyright 2020, Chris Haskins, Nord Games LLC.