Anregon, The Everlasting

Legendary Resistance (3/Day). If Anregon fails a saving throw, he can choose to succeed instead.

Focus of the Dracolord. Anregon can maintain concentration on two different spells at the same time. In addition, he has advantage on saving throws to maintain concentration on spells.

Magic Resistance. Anregon has advantage on saving throws against spells and other magical effects.

Master Chemister. When Anregon casts a spell that deals damage, he can change the spell’s damage to cold, fire, or necrotic

Spellcasting.  Anregon is a 20th-level spellcaster. His spellcasting ability is Intelligence (spell save DC 26, +18 to hit with spell attacks). He has the following wizard spells prepared:

Cantrips (at will): fire bolt, toll the dead, mind sliver, ray of frost, infestation

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

2nd level (3 slots): blur, enlarge/reduce, flaming sphere, ray of enfeeblement

3rd level (3 slots): counterspell, fireball, hold person, slow

4th level (3 slots): confusion, blight, fire shield 

5th level (2 slots): negative energy flood, enervation, wall of fire, dominate person

6th level (1 slot): chain lightning, disintegrate, true seeing

7th level (1 slot): finger of death, teleport, power word pain

8th level (1 slot): antimagic field, maze

9th level (1 slot): power word kill

Multiattack. Anregon can use his Frightful Presence. He then makes three attacks: one with his bite and two with his claws.

Bite. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) piercing damage plus 14 (4d6) necrotic damage.

Claw. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 17 (2d6 + 10) slashing damage.

Tail. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage.

Frightful Presence. Each creature of Anregon's choice that is within 120 feet of him and aware of it must succeed on a DC 21 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to Anregon's Frightful Presence for the next 24 hours.

Necrotic Breath (Recharge 5–6). Anregon exhales black fire in a 90-foot cone. Each creature in that area must make a DC 24 Dexterity saving throw, taking 91 (26d6) necrotic damage on a failed save, or half as much damage on a successful one. Any creature killed this way comes back as a greater zombie

Anregon 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. Anregon regains spent legendary actions at the start of his turn.

Cantrip. Anregon can cast one of his cantrips

Detect. Anregon makes a Wisdom (Perception) check.

Tail Attack. Anregon makes a tail attack.

Wing Attack (Costs 2 Actions). Anregon beats his wings. Each creature within 15 feet of him must succeed on a DC 25 Dexterity saving throw or take 17 (2d6 + 10) bludgeoning damage and be knocked prone. Anregon can then fly up to half its flying speed.