Blanche, The Horseman of Death

Natural Gift (3/ day). If Blanche fails a saving throw, he can choose to succeed instead.

Druidic Training. Blanche is immune to being Frightened, Charmed, Blinded, or Deafened.

Mind and Soul. Blanche automatically succeeds on any saving throws he would make to maintain concentration. 

Elemental Link. If Blanche would deal damage with a spell attack, the spell deals another 12 (4d6) damage of his choice between the following: acid, fire, cold, lightning or thunder (included in the attack).

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

Wildshape. As a bonus action, Blanche can transform into a beast or elemental with a CR rating of 14 or below. While transformed he retains his Intelligence and Wisdom scores, can speak, and use all of his abilities in his chosen form in addition to those of the chosen form.

Natural Communion. Beasts and plants refuse to harm Blanche and he can communicate with them.

Time Spiral. When Blanche drops to 0 hit points, he automatically fails any death saving throws he would make.

Spellcasting. Blanche is a 20th-level spellcaster and can cast without using spell components. his spellcasting ability is Wisdom (spell save DC 19, +13 to hit with spell attacks). He has the following spells prepared:

Cantrips (at will): druidcraft, produce flame, shillelagh, frostbite

1st level (4 slots): entangle, longstrider, cure wounds, thunderwave, faerie fire, find familiar

2nd level (3 slots): animal messenger, dust devil, flaming sphere, moonbeam, spike growth

3rd level (3 slots): call lightning, conjure animals, erupting earth, feign death, plant growth, sleet storm, wind wall

4th level (3 slots): conjure minor elementals, conjure woodland beings, grasping vine, guardian of nature, polymorph, locate creature, stone shape

5th level (3 slots): conjure elemental, contagion, insect plague, commune with nature, wrath of nature, tree stride

6th level (2 slots): conjure fey, druid grove, wall of thorns, transport via plants

7th level (2 slots): fire storm, whirlwind, mirage arcane

8th level (1 slots): earthquake, control weather, sunburst, tsunami

9th level (1 slots): shapechange, storm of vengeance

Multiattack. Blanche makes four dagger attacks.

Blanche's Thorn (Dagger). Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit:  (1d4 + 5) piercing damage and 6 (2d6) cold damage, and the target must make a DC 19 Constitution saving throw, taking 12 (4d6) cold damage on a failed save, or half as much damage on a successful one.

Snowstorm. When Blanche is dealt damage, he can use his reaction to make all creatures within 15 ft of him make a DC 19 Constitution saving throw. On a failed save, the targets' movement becomes 0 for their turn and take 12 (4d6) cold damage, or half as much damage on a successful one.

Blanche, the Horseman of Death 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. Blanche regains spent legendary actions at the start of his turn.

Master of Time (costs 2 actions, recharge 5-6). Blanche casts the spell time stop at will.

Spelltouched. Blanche can cast a spell.

Watcher. Blanche makes a Perception check with advantage.