Ashardalon

Paragon Fortitude (3 Pools of 225 HP). Ashardalon has three separate pools of hit points, each tracked independently. Damage and healing must be applied to a single pool. When a pool is reduced to 0 hit points, all ongoing effects and conditions affecting Ashardalon immediately end. A depleted pool cannot regain hit points until Ashardalon finishes a long rest. If all three pools are reduced to 0 hit points, Ashardalon is slain.

Paragon Fury. Ashardalon gains one additional turn each round for each depleted hit point pool. Determine initiative normally for Ashardalon's first turn. Each additional turn is inserted immediately after any player's turn.

Future Sight. Once per round, when Ashardalon is hit by an attack roll, it can force the attacker to reroll the attack. The new result must be used. Ashardalon must use this feature before damage is rolled.

Aeonfire Backlash. When one of Ashardalon's hit point pools is reduced to 0, all conditions and effects affecting it immediately end. Aeonfire immediately recharges and Ashardalon may immediately use Aeonfire as a reaction. When Ashardalon enters its final hit point pool, it immediately activates Foresight of Ages if it has not already done so.

Fortitude Recharge. Some of Ashardalon's abilities recharge whenever one of its hit point pools is reduced to 0. If an ability specifies it, Ashardalon may immediately use that ability as a reaction when it recharges.

Multiattack. The dragon makes three Rend attacks.

Rend. Melee Attack Roll: +16 to hit, reach 15 ft., one target. Hit: 18 (2d8 + 9) Slashing damage plus 11 (2d10) Force damage.

Open Eyes (Recharge 5–6) Ashardalon opens their eyes. Each creature of Ashardalon's choice within 120 feet that can see it must succeed on a DC 23 Wisdom saving throw. on a Failure, The creature is Frightened for 1 minute. If the save fails by 5 or more, the creature is also Stunned until the end of its next turn. A frightened creature may repeat the save at the end of each of its turns.

Be Still Target creatures in a 30ft sphere must make a DC 23 Charisma Saving throw or lose their reactions and bonus actions until the end of their next turn.

Silence Ashardalon creates an 80 ft aura of silence centering on themself. Spells with verbal components cannot be cast until the beginning of Ashardalon's next turn.

Aeonfire (Recharge 5-6). Constitution Saving Throw: DC 23, each creature in a 120-foot-long, 10-foot-wide Line. On a failed save, creatures take 88 (16d10) Force damage, and the creature's speed is halved and it cannot take reactions until the end of its next turn. On a successful save creatures take half damage.

Be Gone (Recharge 5-6). Ashardalon targets one creature it can see within 120 feet. The target must succeed on a DC 23 Wisdom saving throw or vanish from the battlefield, banished to the birth of the universe. At the end of its next turn, the creature reappears in the nearest unoccupied space to where it vanished taking 88 (16d10) radiant damage. 

Future Sight (1/Day). Ashardalon peers through countless futures. For 1 minute, Ashardalon has advantage on attack rolls, ability checks, and saving throws, and attack rolls against it are made with disadvantage.

Rewind Position (Recharge 5-6). Ashardalon chooses a creature it can see within 120 feet. The target must succeed on a DC 23 Charisma saving throw or be teleported to the space it occupied at the end of its previous turn.

Legendary Reactions. Ashardalon can take one legendary reaction per turn.

Temporal Rebound. When Ashardalon succeeds on a saving throw forced by another creature, choose the creature that forced the save. That creature must succeed on a DC 23 Intelligence saving throw or have disadvantage on the next saving throw it makes before the end of its next turn.

Witness. Whenever Ashardalon takes 40+ damage from one attack, the attack succeeds. But the attacker must make a DC 23 Constitution save. On a failed save the creature is Blinded until end of their next turn.

Slip Between Moments. When a creature ends its turn within 30 feet of Ashardalon, Ashardalon teleports up to 30 feet to an unoccupied space it can see.

Legendary Action Uses: 3. Immediately after another creature's turn, Ashardalon can expend a use to take one of the following actions. Ashardalon regains all expended uses at the start of each of its turns.

Time Slip (Costs 1 Action). Ashardalon teleports up to 60 feet to an unoccupied space it can see. Each creature within 10 feet of the space it left must succeed on a DC 23 Dexterity saving throw or take 16 (3d10) Force damage.

Collapse Distance (Costs 1 Action). Ashardalon chooses a creature it can see within 120 feet. The target must succeed on a DC 23 Charisma saving throw or be teleported to an unoccupied space within 15 feet of Ashardalon.

Fracture Timeline (Costs 1 Action). Choose two creatures Ashardalon can see within 120 feet. Those creatures immediately swap positions.

Chronal Collapse (Costs 2 Actions). Ashardalon chooses a point it can see within 120 feet. Time violently contracts in a 20-foot-radius sphere centered on that point. Each creature in the area must make a DC 23 Constitution saving throw. On a failed save, a creature takes 33 (6d10) Force damage and its speed becomes 0 until the start of its next turn. On a successful save, the creature takes half damage.

Be Not Afraid (Costs 3 Actions) Ashardalon unfolds every eye. Every wing. Every halo. Every creature that can see Ashardalon must make a DC 23 Wisdom save. On a failed save the creature is Stunned Frightened and Blinded Until the end of its next turn. On a successful save the creature is frightened until end of next turn. All creatures (including Ashardalon) are teleported together to a new random location.