Multiattack

The ushabti can use its Breath-Stealing Presence. It then makes two Khopesh attacks and one Medjai's Scepter attack.

Khopesh

Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage plus 9 (2d8) necrotic damage.

Medjai's Scepter

Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 15 (2d8 + 6) bludgeoning damage plus 9 (2d8) necrotic damage.

Breath-Stealing Presence

Each creature of the ushabti's choice within 30 feet of the ushabti and aware of it must succeed on a DC 18 Constitution saving throw or take 9 (2d8) necrotic damage and be unable to speak or breathe for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the ushabti's Breath-Stealing Presence for the next 24 hours.

Enervating Surge (Recharge 5-6)

The ushabti emits waves of necrotic energy. Each creature within 30 feet of the ushabti must make a DC 18 Constitution saving throw, taking 49 (11d8) necrotic damage on a failed save, or half as much damage on a successful one. A creature that can't breathe because of the ushabti's Breath-Stealing Presence has disadvantage on the saving throw. If the saving throw fails by 5 or more, the creature also suffers one level of exhaustion. A Humanoid slain by this effect rises 1d4 hours later as a mummy under the ushabti's control, unless the Humanoid is restored to life or its body is destroyed. The ushabti can have no more than five mummies under its control at one time.