Corellon Larethian, Divine Passage

Fey Ancestor. Corellon has advantage on saving throws against being charmed and magic can’t put them to sleep

Magic Disjunction. Any creature that starts its turn within 240 feet of Corellon and is aware of Corellon's presence must make a DC 26 Wisdom saving throw. On a failed save, the creature has difficultly casting magic. If the creature attempts to cast a spell with a casting time of 1 action, roll a d20. On an 11 or higher, the spell doesn't take effect until the creature's next turn, and the creature must use its action on that turn to complete the spell. If it can't, the spell is wasted. Additionally, a creature affected in this way has disadvantage on Constitution saving throws to maintain Concentration on a spell. On a successful save, the creature becomes immune to Corellon's Magic Disjunction for 24 hours.

A creature affected by Corellon's Magic Disjunction makes another Wisdom saving throw at the end of each of its turns. On a successful save, the effect ends for it. This effect can also be ended by casting greater restoration or remove curse on the target.

Innate Spellcasting.  Corellon's spellcasting ability is Charisma (spell save DC 26, +18 to hit with spell attacks). Corellon can innately cast the following spells, requiring no material components:

At will: charm person, pass without trace, suggestion, Tasha's hideous laughter, ray of frost (as 17th level caster), firebolt (as 17th level caster), shocking grasp (as 17th level caster), magic missile (3rd level version), ray of enfeeblement

3/day each: charm monster, dominate person, mass suggestion, divine word, cone of cold, fireball (5th level version), lightning bolt (5th level version), wall of fire, wall of ice, wall of force

1/day each: dominate monster, globe of invulnerability (8th level version)

Legendary Resistance (5/Day). If Corellon fails a saving throw, they can choose to succeed instead.

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

Magic Weapons. Corellon’s weapon attacks are magical.

Unerring Accuracy. Creatures gain no benefit from half cover or three-quarters cover from Corellon. Attacking at long range doesn't impose disadvantage on Corellon's ranged weapon attack rolls.

Multiattack. Corellon makes 2 attacks with their longbow Amlath'hana or their longsword Sahandrian.

Sahandrian. Melee Weapon Attack: +21 to hit, reach 10 ft., one target. Hit: 26 (3d8 + 13) slashing damage. 

Amlath'hana. Ranged Weapon Attack: +21 to hit, range 1320/5280 ft., one target. Hit: 26 (3d8 + 13) piercing damage.

Shifting of the Planes (Recharge 5-6). Corellon releases pure planar magic in a burst around him. Every creature within 60 feet of Corellon must make a DC 26 Dexterity saving throw or take 56 (16d6) force damage and be pushed 20 ft. directly away from Corellon. Additionally, If the creature is currently concentrating on a spell, that concentration ends. On a successful save the target takes half damage, isn't pushed, and may continue concentrating on spells as normal. 

Change Shape. Corellon magically transforms into any form, while retaining their game statistics (other than their size). While transformed Corellon can choose to gain a flying, climbing and/or swimming speed of 30 ft. as appropriate to the form. This transformation ends if Corellon is reduced to 0 hit points or if they use a bonus action to end it.

Spell Reflection. If Corellon makes a successful saving throw against a spell, or a spell attack misses Corellon, Corellon can choose another creature (including the spellcaster) it can see within 120 feet of it. The spell targets the chosen creature instead of Corellon. If the spell forced a saving throw, the chosen creature makes its own save. If the spell was an attack, the attack roll is rerolled against the chosen creature.

Corellon 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. Corellon regains spent legendary actions at the start of their turn.

Attack (Costs 1 Action). Corellon makes an attack with Amlath'hana or Sahandrian

At will Spell (Cost 1 Action). Corellon casts one of his at-will spells

Planar Scattering (Cost 2 Actions). Corellon casts the scatter spell targeting only enemy creatures

Greater Spell (Costs 3 Actions). Corellon casts one of his innate spells