Aether-Lich

Legendary Resistance (3/Day). If the Aether-Lich fails a saving throw, it can choose to succeed instead.

Rejuvenation. If it has a phylactery called an immortal coil, a destroyed Aether-Lich reforms it's body in 1d10 days, regaining all its hit points and becoming active again. The new body is reformed from the broken etherium pieces which are pulled towards the coil and forms together 5 feet from the Immortal Coil.

Spellcasting. The Aether-Lich is an 16th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 18, +10 to hit with spell attacks). The Aether-Lich has the following wizard spells prepared:

Cantrips (at will): mage hand, Mending, ray of frost

1st level (4 slots): detect magic, magic missile, shield, thunderwave

2nd level (3 slots): Warding Wind, detect thoughts, invisibility, mirror image

3rd level (3 slots): Hypnotic Pattern, counterspell, dispel magic, Erupting Earth

4th level (3 slots): blight, Summon Construct

5th level (3 slots): cloudkill, scrying

6th level (1 slot): chain lightning, globe of invulnerability

7th level (1 slot): finger of death, Mordenkainen’s Sword

8th level (1 slot): dominate monster, power word stun

Magic Resistance. The Aether-Lich has advantage on saving throws against spells and other magical effects.

Immutable Form. The Aether-Lich is immune to any spell or effect that would alter its form.

AEther infused Grasp. Melee Spell Attack: +12 to hit, reach 5 ft., one creature. Hit: 10 (3d6) lightning 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.

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

Master of the 23 Winds (Costs 1 Action). The Aether-Lich gains a fly speed of 40 feet. It provokes no opportunity attacks when moving this way and after moving it's speed it returns to the ground safely.

AEther infused Grasp (Costs 2 Actions). The Aether-Lich uses its AEther infused Grasp.

Frightening Gaze (Costs 2 Actions). The Aether-Lich 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 the lich's gaze for the next 24 hours.

Memory Erosion (Costs 3 Actions). Each non-undead creature within 20 feet of the lich must make a DC 18 Intelligence saving throw against this magic, taking 21 (6d6) psychic damage on a failed save, or half as much damage on a successful one.