Mourncrown, the Sepulchral Aurora

gargantuan undead (titan), neutral-evil · CR twenty-three

by PallidLantern

Armor Class: 21

Hit Points: 370

Speed: 40 ft., fly 60 ft.

Saving Throws: constitution, intelligence, wisdom, charisma

Damage Resistances: Bludgeoning (nonmagical), Cold, Fire, Lightning, Piercing (nonmagical), Slashing (nonmagical)

Damage Immunities: Necrotic, Poison

Condition Immunities: Charmed, Frightened, Paralyzed, Poisoned, Exhaustion

Senses: darkvision 120 ft., truesight 120 ft., passive Perception 24

Languages: Abyssal, Celestial

Challenge: twenty-three

STR 26 (+8)

DEX 14 (+2)

CON 27 (+8)

INT 20 (+5)

WIS 24 (+7)

CHA 27 (+8)

Traits

Legendary Resistance (3/Day). If the creature fails a saving throw, it can choose to succeed instead.
Magic Resistance. The creature has advantage on saving throws against spells and other magical effects.
Turn Resistance. The creature has advantage on saving throws against any effect that turns undead.
Aurora of the Unmourned. Mourncrown sheds a cold, shifting light in a 60-foot radius, which is dim light. A creature that starts its turn in this light must succeed on a DC 22 Wisdom saving throw or be overcome with borrowed grief: it has disadvantage on attack rolls and ability checks until the start of its next turn, and it cannot regain hit points while in the light. A creature that succeeds is immune to this effect for 24 hours.
Deathless Grief. Mourncrown is bound to the unwept sorrow of a buried god. If it is reduced to 0 hit points, its aurora gutters out but is not destroyed: unless every creature that has ever spoken its true name lies dead, it reforms over the same tomb after 1d10 days at full hit points. Only by mourning the buried god properly, an act lost to history, can the aurora be laid to rest for good.

Grave-Light Lash. Melee Weapon Attack. A ribbon of cold sepulchral light lashes out from the aurora's crown. On a hit, the target's hit point maximum is reduced by an amount equal to the necrotic damage taken until it finishes a long rest, and the target cannot regain hit points until the start of Mourncrown's next turn.
Sepulchral Grasp. Melee Weapon Attack. A vast hand of woven grave-light closes on the target. On a hit, a creature of Huge size or smaller is grappled (escape DC 22) and restrained until the grapple ends. While grappled this way, the target takes 18 (4d8) necrotic damage at the start of each of its turns, and Mourncrown can have only one creature grappled at a time.
Wailing Cascade (Recharge 5–6). Mourncrown's crown flares and a cascade of keening light pours out in a 90-foot cone. Each creature in that area must make a DC 22 Constitution saving throw. On a failed save, a creature takes 55 (10d10) necrotic damage and is frightened until the end of its next turn; on a success, it takes half damage and is not frightened. A humanoid reduced to 0 hit points by this damage dies and rises as a shadow under Mourncrown's control at the start of its next turn.

Sink Through Sorrow. Mourncrown dissolves into drifting motes of grave-light and reforms in an unoccupied space it can see within 60 feet. Each creature within 10 feet of the space it leaves and the space it arrives in takes 10 (3d6) necrotic damage.

Sorrow's Rebuke. Mourncrown answers the presumption with a swell of grief. The triggering healing is negated, or the triggering spell fails and its slot is wasted unless the caster succeeds on a DC 22 Charisma saving throw. The creature then takes 16 (3d10) necrotic damage.

Life Drain. The creature targets one creature within 10 feet of it that it can see. The target must succeed on a Constitution saving throw or take necrotic damage.
Pulse of Terror. The creature pulses waves of fear. Each creature within 30 feet must succeed on a Wisdom saving throw or become frightened until the end of its next turn.
Command Undead. The creature targets one undead creature it can see within 60 feet. The target must succeed on a Wisdom saving throw or fall under the creature's control for 1 hour.

Corpse Reanimation. The undead creature animates corpses within 60 feet. Up to four skeletons or zombies rise from the ground in unoccupied spaces and act on initiative count 20 on the next round. These undead are under the creature's control.
Life-Draining Chill. A wave of life-draining cold spreads out in a 30-foot radius centered on the undead creature. Each living creature in that area must succeed on a Constitution saving throw or take cold damage and have its hit point maximum reduced by an amount equal to the damage taken.
Spreading Darkness. Magical darkness fills a 20-foot-radius sphere centered on a point the undead creature can see within 120 feet. The darkness spreads around corners and lasts until initiative count 20 on the next round. Darkvision cannot penetrate this darkness, and no light can illuminate it.

Death Spreads. Plants within the region wither and die. Animals avoid the area. The land itself seems lifeless and cursed.
Crushing Despair. A pall of dread hangs over the region. Creatures that finish a long rest within the region must succeed on a Wisdom saving throw or gain no benefit from the rest.
Evil Omens. Evil omens appear throughout the region. Birds die mid-flight, milk curdles instantly, and mirrors crack spontaneously. Good-aligned creatures feel a strong urge to leave the area.