Volo's Guide to Monsters (5e)
Spellcasting. The blackguard is a 10th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 13, +5 to hit with spell attacks). It has the following paladin spells prepared:
Multiattack. The blackguard makes three attacks with its glaive or its shortbow.
Glaive. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 9 (1d10 + 4) slashing damage.
Shortbow. Ranged Weapon Attack: +3 to hit, range 80/320 ft., one target. Hit: 5 (1d6 + 2) piercing damage.
Dreadful Aspect (Recharges after a Short or Long Rest). The blackguard exudes magical menace. Each enemy within 30 feet of the blackguard must succeed on a DC 13 Wisdom saving throw or be frightened for 1 minute. If a frightened target ends its turn more than 30 feet away from the blackguard, the target can repeat the saving throw, ending the effect on itself on a success.
Any Climate; Any Terrain