Aeon Caelith, Fragment of Still Time

Aura of Lag (Time Drag).

At the start of each creature’s turn within 15 ft., it must succeed on a DC 13 Wis save or its speed is reduced by 10 ft. until the start of its next turn.

Temporal Echo (1/turn).

When Aeon Caelith hits a creature, he can force it to repeat its last movement—moving up to 10 ft. back along its previous path (no opportunity attacks triggered).

Judge’s Mark (Recharge 5–6).

As a bonus action, Aeon marks one creature he can see within 30 ft. The target must make a DC 14 Cha save or be outlined in gold runes until the end of its next turn. The next attack Aeon makes against it has advantage and deals +1d8 radiant damage on hit.

Chrono-Smite.

Melee Weapon Attack: +5 to hit, reach 5 ft., one target.
Hit: 10 (2d8 + 1) radiant damage.

Temporal Pulse (Recharge 6).

Aeon releases a shockwave of force. Each creature of his choice within 15 ft. must make a DC 14 Dex save, taking 13 (3d8) force damage on a failed save or half as much on a success. Creatures that fail are pushed 10 ft. away.

Time Slip (Bonus Action 1/round).

Aeon teleports up to 15 ft. to an unoccupied space he can see, leaving a brief afterimage that lasts until the start of his next turn. The first attack made against him before then has disadvantage.

He can take these at the end of another creature’s turn; he regains spent actions at the start of his turn.

Mythic Trigger (Optional for Epic Feel)

When reduced to 0 HP, the fragment shatters, creating a Core of Still Time (a small orb floating mid-air).

• The Core has AC 10, HP 15.

• While it exists, gravity inverts within a 10-ft. radius and time warps, so each creature within must make a DC 12 Dexterity save or be pulled 5 ft. toward it at the end of its turn.
  Destroying the Core ends the effect.