Exethanter

If Exethanter fails a saving throw, it can choose to succeed instead.

If it has a phylactery, a destroyed lich gains a new body in 1d10 days, regaining all its hit points and becoming active again. The new body appears within 5 feet of the phylactery.

Exethanter has advantage on saving throws against any effect that turns undead.

Melee Spell Attack Roll: +12 to hit, reach 5 ft., one creature. Hit: 10 (3d6) cold damage. The target must succeed on a DC 18 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Exethanter casts a cantrip.

Exethanter uses its Paralyzing Touch.

Exethanter fixes its gaze on one creature it can see within 10 feet of it. The target must succeed on a DC 18 Wisdom saving throw against this magic or become frightened for 1 minute. The frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a target's saving throw is successful or the effect ends for it, the target is immune to Exethanter's gaze for the next 24 hours.

Each non-undead creature within 20 feet of Exethanter must make a DC 18 Constitution saving throw against this magic, taking 21 (6d6) necrotic damage on a failed save, or half as much damage on a successful one.

Exethanter is an 18th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 20, +12 to hit with spell attacks). Exethanter has the following wizard spells prepared:

Cantrips: mage hand, prestidigitation, ray of frost