Master of Life and Death. When Vitamorde hits a target with Shi or Seimei, he heals for half the damage dealt (rounded up).

Magecraft Mastery. Vitamorde can concentrate on 2 spells at once. Additionally, he adds +10 to each constitution save made to maintain concentration on one of his spells, and may use a legendary action in place of a missing spell slot of 3rd level or lower (see legendary actions)

Spellcasting. Vitamorde is a 30th-level spellcaster. His spellcasting ability is wisdom (spell save DC 24, +19 to hit with spell attacks). He has following spells prepared:
Cantrips (at will): Acid Splash, Chill Touch, Druidcraft, Eldritch Blast, Mind Sliver, Sapping Sting, Spare the Dying, Toll the Dead

1st level (6 slots): Detect magic (at will), Shield, Cause Fear, Cure Wounds, Faerie Fire, False Life, Goodberry, Guiding Bolt, Healing Word, Inflict Wounds, Magic Missile, Ray of Sickness

2nd level (6 slots): Alter Self (at will), Enlarge/Reduce, Flock of Familiars, Gentle Repose, Mind Spike, Blindness/Deafness, Darkness, Healing Spirit, Prayer of Healing, Ray of Enfeeblement, Silence

3rd level (5 slots): Counterspell (spellcasting ability is +5 for the purpose of this spell), Dispel Magic (spellcasting ability is +5 for the purpose of this spell), Fear, Remove Curse, Revivify, Animate Dead, Bestow Curse, Mass Healing Word, Life Transference, Magic Circle, Major Image, Speak With Dead, Spirit Shroud, Summon Undead, Vampiric Touch

4th level (3 slots): Death Ward (at will), Gravity Sinkhole, Phantasmal Killer, Blight, Elemental Bane, Hallucinatory Terrain, Shadow of Moil

5th level (3 slots): Far Step, Telekinesis, Wall of Force, Animate Objects, Antilife Shell, Circle of Power, Contagion, Dense Macabre, Dispel Evil and Good, Hallow, Negative Energy Flood, Raise Dead

6th level (3 slots): Contingency, Harm, Arcane Gate, Circle of Death, Create Undead, Gravity Fissure, Guards and Wards, Magic Jar, Mental Prison, Primordial Ward, Soul Cage, Wall of Thorns, Sunbeam

7th level (2 slots): Power Word Pain, Crown of Stars Finger of Death, Forcecage, Magnificent Mansion, Mirage Arcane, Resurrection, Regenerate, Sequester, Symbol, 

8th level (2 slots): Dark Star, Feeblemind, Glibness, Illusory Dragon, Power Word Stun, Mighty Fortress, Maddening Darkness, Telepathy

9th level (2 Slots): Power Word Kill, Astral Projection, Imprisonment, Invulnerability, Mass Heal, Power Word Heal, Ravenous Void, Psychic Scream, Shapechange

10th level (1 slot): Animus Blizzard

Reaper's Onslaught. Vitamorde makes 1 attack with Seimei, 1 attack with Shi, and casts a cantrip and a leveled spell as part of the same attack action

Seimei. Melee Weapon Attack: +18 to hit, reach 5 ft., 1 target. Hit: 18 (1d12 + 9) radiant damage.

Shi. Melee Weapon Attack: +18 to hit, reach 10 ft., 1 target. Hit: 18 (1d12 + 9) necrotic damage.

Ebb and Flow of Life and Death. As a bonus action, Vitamorde can challenge the life-force of an enemy within 30 ft., that has not yet been targeted with this ability, with the highest constitution score (his choice, if tied). The target must make a Constitution saving throw (DC 25) or be knocked unconscious by the violent maelstrom of power ripping at their soul. The affected creature can re-attempt the save after being attacked, as well as at the start of each of their turns. at the start of every subsequent turn after being knocked unconscious, the DC decreases by 10 (to a minimum of 5). After a creature succeeds the saving throw, they awaken, and are immune to this effect for 24 hurs.

Absorb Life and Death. When a creature within 60 ft. of Vitamorde casts a spell that would heal a creature, Vitamorde can use his reaction to heal for that same amount.

Vitamorde has 3 legendary actions

0-2nd level spell (Costs 1 Action). Vitamorde casts a cantrip, or casts a 1st/2nd level spell.

3rd-4th level spell (Costs 2 Actions). Vitamorde casts a 3rd or 4th level spell.

Inochi wo Ataeru Karitori (Costs 1 Action). Vitamorde makes 1 weapon attack with Seimei, and 1 attack with Shi.

Mana Surge (costs 1-3 actions). Vitamorde can substitute his legendary actions for spell slots. a level 1 spell costs 1 action, a level 2 spell costs 2 actions, and a level 3 spell costs all 3 legendary actions