Aratorin, the Winter Knight

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

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

Mantle of Winter. Aratorin counts as a Fey for spells and abilities that target that creature type.

Bane of Faerie. Aratorin is vulnerable to slashing and piercing damage from weapons made of iron or steel.

Spellcasting. Aratorin is an 18th-level spellcaster. His spellcasting ability is Wisdom (spell save DC 18, +10 to hit with spell attacks). He has the following spells prepared:

Cantrips (at will): druidcraft, mending, primal savagery, frostbite

1st level (4 slots): armor of agathys, ice knife, faerie fire, speak with animals, frost fingers

2nd level (3 slots): animal messenger, rime's binding ice, hold person, wither and bloom

3rd level (3 slots): conjure animals, sleet storm, summon fey, water walk

4th level (3 slots): dominate beast, ice storm, blight, elemental bane

5th level (3 slots): commune with nature, cone of cold, tree stride

6th level (1 slot): wall of ice, freezing sphere, investiture of ice

7th level (1 slot): power word pain

8th level (1 slot): maddening darkness

9th level (1 slot): gate

Rimesilver Scimitar. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) slashing damage and 12 (4d6) cold damage.

Change Shape (2/Day). Aratorin magically polymorphs into a beast or elemental with a challenge rating of 6 or less, or a Winter Wolf, and can remain in this form for up to 9 hours. Aratorin can choose whether his equipment falls to the ground, melds with his new form, or is worn by the new form. Aratorin reverts to his true form if he dies or falls unconscious. Aratorin can revert to his true form using a bonus action on his turn.

While in a new form, Aratorin retains his game statistics and ability to speak, but his AC, movement modes, Strength, and Dexterity are replaced by those of the new form, and he gains any special senses, proficiencies, traits, actions, and reactions (except class features, legendary actions, and lair actions) that the new form has but that he lacks. He can cast his spells with verbal or somatic components in his new form.

The new form’s attacks count as magical for the purpose of overcoming resistances and immunity to nonmagical attacks.

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

Melee Attack. Aratorin makes one melee attack with either his Rimesilver Scimitar or a weapon available to him while using his Change Shape feature.

Swiftcast. Aratorin casts one spell of 3rd level or lower.

Fey Step. Aratorin teleports up to 30 feet in any direction. This does not provoke opportunity attacks.