Chronal Wraith

Ephemeral. The Chronal wraith can't wear or carry anything.

Freedom of Movement. The Chronal wraith ignores difficult terrain, and magical effects can't reduce its speed or cause it to be restrained.

Immutable Form. The Chronal wraith is immune to any spell or effect that would alter its form.

Magic Resistance. The Chronal Wraith has advantage on saving throws against spells and other magical effects.

Time is of the essence. The Chronal Wraith ignores a creature's immunity to psychic damage, a creature is considered to be resistant to the wraith's damage instead of immune. If a creature is resistant to psychic damage the Chronal Wraith ignores the resistance completely.

Multiattack. The Chronal wraith makes four attacks: Three with its Chronal Tap and one with Temporal Lance.

Chronal Tap. Melee Weapon Attack: +12 to hit, reach 10 ft., 1 target. Hit: 80 (10d12 + 20) Force damage. On a hit a creature must make a DC 21 constitution saving throw. On a failure the creature gains 1 point of exhaustion. On a success, nothing happens. If you are dropped to 0 hp or killed by the exhaustion effect of this attack, you can not be resurrected by any means short of a wish spell.

Temporal Lance. Ranged Weapon Attack: +12 to hit, range 30/120 ft., 1 target.   Hit: 47(14d6 + 10)Psychic damage. If you are dropped to 0 hp by this attack you are dead and can not be resurrected by any means other than wish or true resurrection.