Gargantuan Dragon, Any Neutral Alignment
AC 24 (natural armor)    Initiative +2 (12)
HP 536 (29d20 + 232)
Speed 40 ft., Fly 80 ft., Swim 40 ft., Climb 40 ft.
Mod Save
STR 28 +9 +9
DEX 14 +2 +10
CON 26 +8 +16
Mod Save
INT 27 +8 +8
WIS 18 +4 +12
CHA 23 +6 +14
Skills Arcana +16, History +24, Perception +20, Stealth +18
Senses Truesight; Passive Perception 30
Languages All
CR 26 (XP 90,000; PB +8)
Traits

Back to the Beginning. If Aeonvenarra falls to zero hit points, her soul travels through time and space and into the invulnerable egg she hatched from. In 1d100 years she will be reborn as a time dragon wyrmling. Her mythic lair action is triggered.

See it Coming. Aeonvenarra has advantage on all saving throws.

Legendary Resistance (5/Day). If Aeonvenarra fails a saving throw, she can choose to succeed instead.

Actions

Multiattack. Aeonvenarra can use Time Quagmire. She then makes three Rend attacks.

Rend. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 22 (3d8 + 9) slashing damage plus 10 (3d6) force damage.

Time Quagmire. Each creature of Aeonvenarra's choice that is within 120 feet of her must succeed on a DC 24 Wisdom saving throw or become Slowed for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to Aeonvenarra's Time Quagmire for the next 24 hours.

Slipping Sands (Recharge 5–6). Aeonvenarra exhales a cloud of ash in a 90-foot cone. Each creature in that area must make a DC 24 Wisdom saving throw, taking 72 psychic damage on a failed save, or half as much damage on a successful one, as their mind is flooded with existential dread at images of themselves and their loved ones aging and decaying into dust.

Time Stop (1/Day). Aeonvenarra casts Time Stop.

Reactions

 

Aeonvenarra can take up to three reactions per round but only one per turn.

Rewind. When Aeonvenarra is hit with an attack, she spins back time, forcing the attacker to re-roll the attack roll at disadvantage.

 

Legendary Actions

Aeonvenarra 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. She regains spent legendary actions at the start of her turn.

Rend Attack. Aeonvenarra makes a Rend attack.

Hynotic Wings (Costs 2 Actions). Aeonvenarra unfurls her wings, swirling with sparkling galaxies. Each creature that can see her must succeed on a DC 24 Wisdom saving throw or suffer the effects of the spell Hypnotic Pattern. She can then immediately teleport up to 120 feet to an unoccupied space she can see. 

Mythic Actions

Out of Time. When Aeonvenarra is brought to 0 hp and returns to her egg, the pocket realm her lair exists in ejects any creatures that were inside, casting them adrift in the Astral Sea.

Description

Aeonvenara is not bound by time—she is time. A gargantuan dragon of impossible size and unknowable age. Unlike many dragons, Aeonvenara does not hoard gold. She hoards history.

Entire towns, kingdoms, civilizations—gone in the blink of a cosmic eye—vanished into her gaping, celestial maw. She opens rifts in the sky, yawns wide her jaw, and consumes times and places whole. Not to destroy them, but to preserve them, safely tucked in her infinite gullet where time stands still. She’s a living archive, a ravenous museum. 

Lair and Lair Actions

Aeonvenarra's lair exists in a pocket realm in the Astral Plane. It is large enough to hold her enormous form comfortably as well as her collections of tomes and artifacts related to lost civilizations. 

Lair Actions

On initiative count 20 (losing initiative ties), Aeonvenarra can take one of the following lair actions; she can't take the same lair action two rounds in a row:

Ravages of Time. Each enemy present in the lair must make a DC 24 Constitution saving throw. On a failed save, the targets appear to rapidly age.  For one round, they deal only half damage with weapon attacks that use Strength and their movement speed is halved.

Historic Hero. Aeonvenarra summons a legendary warrior from somewhere in her gullet to do battle at her side. Use the Warrior Commander stat block. 

 

 

Habitat: Planar (Astral Plane)

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