Chronos, The Titan of Time

Legendary Resistances (5/Day). If Chronos fails a saving throw, he can choose to succeed instead.

Temporal Ascendancy. When Chronos is reduced to 0 hit points, he does not die. Instead, time rewinds, and he regains 325 hit points. He unleashes his true power, and his Aura of Temporal Distortion extends to 240 feet. In this state, his spellcasting recharges, and he gains access to additional mythic actions.

Aura of Temporal Distortion. Within 120 feet of Chronos (240 feet in mythic form), time warps unnaturally. Creatures of Chronos’s choice in the area cannot benefit from extra movement (such as Dash or Haste). When a creature in the aura uses their reaction, they must succeed on DC 24 constitution saving throw, on a failure they lose their reaction. Additionally, creatures age 1 year for every minute spent within the aura.

Innate Spellcasting. Chronos’s spellcasting ability is Charisma (spell save DC 24). He can innately cast the following spells, requiring no material components:

At Will: Detect Thoughts, Dispel Magic, Time Stop (as a 9th-level spell)

3/Day Each:  Reverse Gravity, Disintegrate, Power Word Stun

1/Day Each:  Wish, Meteor Swarm, Divine Word, Foresight (self only)

Titanic Form. Chronos can move through the space of creatures smaller than Gargantuan without treating the area as difficult terrain. Creatures in his space must succeed on a DC 24 Dexterity saving throw or take 36 (8d8) bludgeoning damage and be knocked prone.

Time Reaper. Chronos wields a massive scythe infused with temporal magic. This weapon deals an additional 6d8 force damage and alters time around the struck target.

Multiattack. Chronos makes three attacks: two with his Scythe of Ages and one with Temporal Shift.

Scythe of Ages. Melee Weapon Attack: +18 to hit, reach 15 ft., one target. Hit: 36 (6d10 + 10) slashing damage plus 27 (6d8) force damage. If the target is a creature, it must succeed on a DC 22 Constitution saving throw or lose its next turn as time unravels around it.

Temporal Shift (Recharge 5–6). Chronos sends a ripple of temporal energy through time. Each creature of his choice within a 60-foot radius must succeed on a DC 24 Constitution saving throw or be aged 5d10 years. A creature that ages beyond its natural lifespan dies instantly.

Chrono-Wave (1/Day). Chronos sends a wave of destructive time magic in a 120-foot cone. Each creature in the area must make a DC 24 Dexterity saving throw, taking 88 (16d10) force damage on a failed save, or half as much on a success. Structures and magical effects are destroyed in the cone’s area unless they succeed on a DC 24 Strength or Constitution save (DM’s discretion).

Echo of the Past. Chronos summons a shadow of himself from a previous moment in time, which mirrors his next attack or ability, forcing the target to make two separate saving throws or attack rolls against the same effect.

Rewind Strike. If Chronos misses an attack, he can rewind the moment, re-rolling the attack with advantage.

Paradox Shield. When Chronos is hit by an attack, he can shift his position in time, causing the attack to target an illusionary afterimage instead. The attack automatically misses.

Temporal Reversal. When an enemy within 60 feet successfully saves against one of Chronos’ spells or abilities, he can force them to reroll the saving throw, taking the new result.

Echoed Counterattack. When a creature within melee range attacks Chronos, he summons a phantom afterimage from the past to immediately retaliate, making a melee attack against the attacker.

Chronos can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time, and only at the end of another creature's turn. Chronos regains spent legendary actions at the start of his turn.

Temporal Strike. Chronos makes one Scythe of Ages attack.

Distort Reality (Costs 2 Actions). Chronos shifts time slightly, allowing himself or one ally to reroll a saving throw, ability check, or attack roll.

Time Stop (Costs 3 Actions). Chronos casts Time Stop without expending a spell slot.

When Chronos activates his Temporal Ascendancy, he gains access to the following mythic actions:

Mythic Temporal Strike (Costs 2 Actions). Chronos makes a Scythe of Ages attack. On a hit, the target is banished to a pocket of frozen time for 1d4 rounds. A creature banished this way cannot act, move, or be targeted but returns in the same state once the effect ends.

Temporal Collapse (Costs 3 Actions). Chronos creates a localized implosion of time in a 60-foot radius centered on himself. Each creature in the area must make a DC 24 Constitution saving throw, taking 72 (16d8) force damage and becoming paralyzed until the end of Chronos’s next turn on a failed save.

Rewrite Fate (Costs 3 Actions). Chronos rewinds time in the immediate area. Each creature of his choice within 120 feet must reroll one successful saving throw or attack roll they made in the last round.