Voklon, the Crimson Hand

Aura of Conquest. Any creature frightened of Voklon within 10 feet of it has it's speed reduced to 0 and the creature takes 5 points of psychic damage if it starts its turn within the aura.

Legendary Resistance. Once a day, if Voklon were to fail a saving throw, it can instead chose to succeed it instead.

Hand of Vecna. Voklon bears the Hand of Vecna, and has its abilities as described in the Dungeon Master's Guide. While attuned to the Hand, Voklon has the following abilities

• Voklon can cast mage hand
• Voklon can cast mass suggestion once a day. After casting, roll a d6. On a 6, this ability immediately recharges
• Voklon has disadvantage on saving throws against poison
• Melee and spell attacks made with the left hand deal an additional 2d8 cold damage
• Each day, Voklon can use the Hand to cast slow, sleep, and teleport once a day each. Because Voklon is evil, the Hand's ability to compel it to commit evil acts is negated.

Eldritch Mind. Voklon has advantage on Constitution saving throws to maintain concentration on spells and spell-like abilities.

Lay On Hands. Voklon can, as an action, touch a creature and restore hit points to it. Voklon has a pool of 50 hit points for this that recharges after a long rest.

Spellcasting. Voklon is a 10th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 17, +9 to hit with spell attacks). Voklon has following paladin spells prepared:
1st level (4 slots) : command, protection from evil and good, thunderous smite, armor of Agathys
2nd level (3 slots): branding smite, find steed, hold person, spiritual weapon
2nd level (3 slots):  blinding smite, dispel magic, bestow curse, fear

Pact Magic. Voklon is a 5th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 17, +9 to hit with spell attacks). Voklon has following warlock spells prepared, and regains the use of them after a short or long rest.  
Cantrips (at will): eldritch blast, green flame blade, light 
1st-5th level (2 3rd level slots): shield, wrathful smite, blur, blink, elemental weapon, clairvoyance, detect thoughts, crown of madness

Multiattack. Voklon can make two attacks with its maul, or two attacks with the Bloodletting Blade, or three attacks with Eldritch Blast.

Maul. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit:  12 (2d6+5) bludgeoning damage and 9 (2d8) cold damage. 

Bloodletting Blade. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit:  11 (1d8+7) slashing damage, 7 (2d6) necrotic damage and 9 (2d8) cold damage (27 average), or 28 (1d10+7+2d6+2d8) damage apportioned as above if wielded with both hands.

Eldritch Blast. Ranged Spell Attack: +9 to hit, range 120 ft., one target. Hit: 5 (1d10) force damage. While the Bloodletting Blade is drawn, this attack deals an extra 5 points of necrotic damage.

Conquering Presence (Long Rest). Each creature within sight within 30 feet of Voklon makes a Wisdom saving throw (DC 17). On a failed save, the frightened creature can repeat this saving throw at the end of each of its turns, ending the effect on itself on a success. 

Hex of the Warring One (Short Rest). as a bonus action, a target within 30 feet that Voklon can see is cursed for 1 minute. The curse ends early if the target dies. Attacks Voklon makes against the cursed target deal an additional 5 points of damage. Any attack roll Voklon makes against the target is a critical hit on a roll of 19 or 20. If the cursed target is reduced to 0 hit points, Voklon regains 9 hit points.  

Bloodmark of Binding (Long Rest). As a bonus action, Voklon targets a creature it can see within 30 feet. The target must succeed on a DC 17 Strength saving throw or have their speed be reduced to 0 and they can’t use reactions. At the end of each of its turns, the cursed creature can make another Strength saving throw. On a success, this curse ends.

Reactionary Spellcasting. Voklon can cast hellish rebuke if damaged by a creature, or shield if targeted by an attack.

Voklon only has use of its Legendary Actions while the Bloodletting Blade is drawn. Voklon can use 3 actions per round. 

Tactical Reposition. Voklon can move its full speed. While this movement can provoke opportunity attacks, attacks of opportunity made against Voklon while using this ability are made at disadvantage.

Spellcasting. Voklon can cast a spell or use a spell-like ability. If it casts a concentration spell while already concentrating on another spell, the spell cast as part of this action lasts until Voklon's next turn without breaking concentration of the already cast spell.

Disciple of War. Voklon takes the multiattack action, but must select a different target for each attack.

Tide of Blood. A wave of blood spills forth from Voklon, and any creature within a 30 foot radius must succeed on a DC 17 Strength saving throw or be pushed to the edge of the 30 foot radius and be knocked prone. Additionally, any creature within 10 feet of Voklon when this ability is used must succeed on a DC 17 Constitution saving throw or be poisoned for the next 1d4+1 rounds. 

When Voklon is dropped to 0 hit points, it does not make death saving throws. Instead, each round on its turn in the initiative order, a wave of crimson-colored necrotic energy bursts forth. Any creature within 60 feet of Voklon must succeed a DC 17 Constitution saving throw or take 18 (4d8) necrotic damage. This effect endures for 5 rounds, after which the body of Voklon dries and withers into dust, exsanguinated.