b'Seething Oblivion \n'b'  Medium   undead ,  neutral evil  \n'b'  Armor Class  15  Hit Points  246 (29d8 + 116)  Speed  0 ft., fly 60 ft. (hover)\n'b' STATS STR: 7 (-2) DEX:  20 (+5)  CON:  19 (+4)  INT:  14 (+2)  WIS:  15 (+2)  CHA:  20 (+5)  \n'b'\n'b'\n'b'\n'b'\n'b'\n'b'     Damage Vulnerabilities  radiant \n'b' 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) \n'b' Special Traits \n'b'   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. \n'b'  Legendary Resistance (3/Day) . When the seething oblivion fails a saving throw, it can choose to succeed instead. \n'b'  Specter Servants . The seething oblivion\xc2\x92s Life Drain and Create Specter abilities can both create specters under the seething oblivion\xc2\x92s control. The seething oblivion can have no more than 11 total specters under its control at a time. \n'b'  Sunlight Sensitivity . While in sunlight, the seething oblivion has disadvantage on  attack  rolls, as well as  Wisdom  ( Perception ) checks that rely on sight. \n'b'  Actions \n'b'   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\xc2\x92s control. \n'b'  Necrotic Lash .  Melee Weapon Attack : +11 to hit, reach 5 ft., one creature.  Hit : 22 (5d8) necrotic damage. \n'b'  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\xe2\x80\x99s 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\xc2\x92s control. \n'b'  Legendary Actions \n'b' 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\xe2\x80\x99s turn. The seething oblivion regains spent legendary  actions  at the start of its turn. \n'b'   Shift . The seething oblivion flies up to half its fly speed, without provoking opportunity attacks. \n'b'  Hateful Lash . The seething oblivion makes a Necrotic Lash  attack . \n'b'  Create Specter (Costs 2 Actions) . The seething oblivion uses its Create Specter ability.'