Echo

Aura of Cacophony. The demon's presence is extremely distracting. Each creature within 100 feet of the echo demon and that can hear it has disadvantage on concentration checks.

Iron Claws. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) slashing damage and if the creature is wearing metal armor, it must make a successful DC 15 Constitution saving throw or be deafened until the end of its next turn.

Everywhere at Once (Recharge 5-6). The echo demon teleports up to 60 feet to an unoccupied space. Immediately after teleporting, it can make an iron claws attack with advantage as a bonus action.

Echoes of the Abyss (1/Day). The echo demon summons horrible wails from the deep crevasses of the Abyss. Creatures within 60 feet who can hear the wails must succeed on a DC 15 Wisdom saving throw or be stunned until the start of the echo demon's next turn. An affected creature continues hearing the troubling echoes of these cries until it finishes a long rest, and it has disadvantage on Intelligence checks until then.