Xartug, The Hand of Vecna

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

Legendary Resistance. 3/day If Xartug fails a saving throw, he can choose to succeed instead.

Inescapable Destruction. Necrotic damage you deal ignores resistance.

Touch of Death. (3/day) (No Action) Xartug can add 45 points of necrotic damage to a melee attack.

Marshal Undead. Unless Xartug is incapacitated, it and undead creatures of its choice within 60 feet of it have advantage on saving throws against features that turn undead.

Spellcasting. Xartug is a 20th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 21, +13 to hit with spell attacks). It has the following cleric spells prepared:

At will: chill touch, thaumaturgy

1st level (4 slots): shield of faith, inflict wounds

2nd level (3 slots): hold person, silence

3rd level (3 slots): dispel magic, animate dead, haste, spirit guardians, vampiric touch

4th level (3 slots): blight, banishment

5th level (3 slots): destructive wave (necrotic), contagion

6th level (2 slots): harm, word of recall (temple which has forbiddance cast on it)

7th level (2 slots): finger of death

8th level (1 slot): control weather

9th level (1 slot): gate, power word kill

Multiattack. Xartug makes three longsword attacks.

Fang. Melee Weapon Attack: +18 to hit, reach 5 ft., one target. Hit: 17 (1d8 + 12) slashing damage, plus 36 (8d8) necrotic damage. If an attack reduces a character to 0 hit points, Xartug leaves Fang in the creature and absorbs their soul, granting him temporary hit points equal to half the creatures maximum hit points. This effect does not stack, so the next time it reduces a creature to 0 hit points it only replaces the current temporary hit points if the new temp hit points would exceed current amount. Any creature's soul that is absorbed by Fang is destroyed. Only Wish can return this creature to life.

Hellfire Orb (1/Day). Xartug hurls a magical ball of fire that explodes at a point it can see within 120 feet of it. Each creature in a 20-foot-radius sphere centered on that point must make a DC 21 Dexterity saving throw. The sphere spreads around corners. A creature takes 35 (10d6) fire damage and 35 (10d6) necrotic damage on a failed save, or half as much damage on a successful one.

Agressive. As a bonus action, Xartug can move up to his speed towards an enemy of his choice that he can see or hear.

Shield Master Shove. If you take the Attack action on your turn, you can use a bonus action to try and shove a creature within 5 ft. of you with your shield.

Parry. Xartug adds 6 to its AC against one melee attack that would hit it. To do so, Xartug must see the attacker and be wielding a melee weapon.

Shield Evasion. If an effect allows half damage on success, Xartug can use his reaction to take no damage.

War Caster. Xartug uses his reaction to make an opportunity attack with a spell.

Xartug has 3 Legendary Actions:

Chill Touch. (1 action) Xartug can cast Chill Touch at will at 2 targets within 5 ft of each other.

Fang. (1 action) One melee attack.

Move. (1 action) Xartug moves up to his speed without provoking an opportunity attack.

Casting. (1 action) Xartug casts any spell for which he has a spell slot