Chaos Knight

Magic Resistance. The Chaos Knight has advantage on saving throws against spells and other magical effects.

Magic Weapons. The Chaos Knight's weapon attacks are magical.

Mount. The Chaos Knight rides atop a Chaos Steed. It's movement is 60 feet.

Charge. If the Chaos Knight moves at least 40 feet straight toward a target and then hits it with a polearm attack on the same turn, the target takes an extra 19 (3d12) slashing damage.

Mounted Combatant. While the Chaos Knight is mounted and isn't incapacitated, it has advantage on melee attack rolls against unmounted creatures smaller than it's mount. Also the Chaos Knight does not have disadvantage when it uses a bladed lance to Attack a target within 5 feet of it while mounted. Chaos Knights can force an attack targeted at their mount to target them instead. If their mount is subjected to an effect that allows it to make a Dexterity save to take only half damage, it takes no damage if it succeeds and half damage if it fails.

Seasoned Rider. The Chaos Knight has advantage on saving throws made to avoid falling off it's mount. If the Chaos Knight falls off it's mount and descends no more than 10 feet, it can land on its feet and it isn't incapacitated. The Chaos Knight can dismount it's Chaos Steed as a free action, requiring no movement.

Spellcasting. The Chaos Knight is a 8th-level spellcaster. It's spellcasting ability is Charisma (spell save DC 17, +9 to hit with spell attacks). It has the following spells prepared:

1st level (4 slots): cause fear, false life, ray of sickness

2nd level (3 slots): ray of enfeeblement, blindness/deafness,darkness

3rd level (3 slots): revivify, life transference, vampiric touch

4th level (2 slots): blight, shadow of moil

Multiattack. The knight makes three melee attacks.

Longsword. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 10 (1d8 + 5) slashing damage, plus 9 (2d8) necrotic damage.

Polearm. Melee Weapon Attack:  +10 to hit, reach 10 ft., one target. Hit: 12 (1d12 + 5) slashing damage, plus 9 (2d8) necrotic damage. One-handed on mount. 

Parry. The Chaos Knight adds 5 to its AC against one melee attack that would hit it. To do so, the knight must see the attacker and be wielding a melee weapon.