Aura of Terror.

When a hostile creature within 5 feet of the black gauntlet makes an attack roll or a saving throw, it has disadvantage on the roll. Creatures that are immune to the frightened condition are immune to this trait.

Spellcasting.

The black gauntlet is a 5th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). It has the following cleric spells prepared:

Cantrips (at will): guidance, sacred flame, thaumaturgy
1st level (4 slots): bane, bless, cure wounds, guiding bolt (see "Actions" below)
2nd level (3 slots): blindness/deafness, hold person, silence
3rd level (2 slots): sending, spirit guardians

Tactical Discipline.

The black gauntlet has advantage on all ability checks and saving throws made during combat.

Actions

Multiattack.

The black gauntlet makes two attacks with its mace.

Mace.

Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) bludgeoning damage plus 13 (3d8) necrotic damage.

Guiding Bolt (1st-Level Spell; Requires a Spell Slot).

Ranged Spell Attack: +7 to hit, range 120 ft., one creature. Hit: 14 (4d6) radiant damage, and the next attack roll made against the target before the end of the black gauntlet's next turn has advantage. If the black gauntlet casts this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for each slot level above 1st.

Black Gauntlet of Bane