Belisarius

Amulet of proof against detection and location. Hidden from divination magic.

Book of Dark Divination. A demon or cultist that serves the demon lord Baphomet can read the dark tome and learn its secrets. Belisarius gets warnings about imminent problems and threats several times per day, both big and small.    

Rotting Presence. When any creature that isn't a demon starts its turn within 30 feet one or more bulezaus, that creature must succeed on a DC 15 Constitution saving throw or take 1d6 poison damage and 1d6 necrotic damage plus 1 necrotic damage for each bulezau within 30 feet of it.

Standing Leap. The bulezau's long jump is up to 20 feet and its high jump is up to 10 feet, with or without a running start.

Sure-Footed. The bulezau has advantage on Strength and Dexterity saving throws made against effects that would knock it prone.

Unerring Tracker. As a bonus action, this creature magically creates a psychic link with one creature it can see. For the next hour, as a bonus action this creature learns the current distance and direction to the target if it is on the same plane of existence. The link ends if this creature is incapacitated or if it uses this ability on a different target.

Incite the Hunters (Recharges after a Short or Long Rest). As an action, this creature allows each ally within 30 feet of it that has the Unerring Tracker trait to make one weapon attack as a reaction against the target of that ally’s Unerring Tracker.

Labyrinthine Recall. This creature can perfectly recall any path it has traveled.

Innate Spellcasting. Belisarius's innate spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). Belisarius has the following spells prepared, requiring no material components:

1/day: Hunters Mark (1st level), Beast Sense (2nd level), Slow (3rd level)

Multiattack. The Belisarius makes three melee attacks, two with the flesh render, and one with the barbed tail.

Flesh Render (long sword +1). Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 9 (1d10 + 4) slashing damage and 4 (1d8) acid damage.

Barbed Tail. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 10 (1d12 + 4) piercing damage. If the target is a creature, it must succeed on a DC: 15 Constitution saving throw against disease or take 13 (3d8) poison damage and become poisoned until the disease ends. While poisoned in this way, the target sports festering boils, coughs up flies, and sheds rotting skin, and the target must repeat the saving throw after every 24 hours that elapse. On a successful save, the disease ends. On a failed save, the target's hit point maximum is reduced by 4 (1d8). The target dies if its hit point maximum is reduced to 0.

Horned One’s Call. When the cambion targets only one creature with the attacks of its Multiattack, it can choose one ally it can see within 30 feet. That ally can use its reaction to make one melee attack against a target of its choice.