Warlock Knight Executor

Martial Advantage. Once per turn, the knight can deal an extra 7 (2d6) damage to a creature it hits with a weapon attack if that creature is within 5 feet of an ally of the knight that isn't incapacitated.

Iron Sky Spellcasting. The knight's spells deal radiant damage instead of its usual damage type. 

Spellcasting. The knight is a 10th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 13, +5 to hit with spell attacks). The Knight has the following spells prepared:

Cantrips (at will): eldritch blast, prestidigitation, message, shocking grasp

1st level (4 slots): hellish rebuke, shield, thunderwave, magic missile

2nd level (3 slots): misty step, shatter

3rd level (2 slots): melf's minute meteors

Multiattack. The knight makes two glaive attacks or throws three shurikens.

Ironfell Glaive. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 9 (1d10 + 4) slashing damage + 5 (1d10) radiant damage.

Ironfell Shuriken. Ranged Weapon Attack: +7 to hit, reach 30/60 ft., one target.  Hit: 7 (1d4 + 4) piercing damage + 3 (1d4) radiant damage.

Eldritch Blast (two beams). Ranged Spell Attack: +5 to hit, reach 120 ft., one target. Hit: 7 (1d10 + 2) radiant damage. 

Dark One's Own Luck (1/day). If the knight fails an ability check or a saving throw, they can add 1d10 to their roll.

Iron Sky Pursuit. When a creature within 30 ft of the knight begins movement away from the knight, the knight can fly up to 30 ft towards the creature, before that creatures moves.