Greatsword: Melee Weapon Attack: +6 to hit, reach 5 ft, one target.
Hit: 13 2d8+4 bludgeoning damage.
Incorporeal Movement. The allip can move through other creatures and objects as if they were difficult terrain.
Unusual Nature. The allip doesn't require air, food, drink, or sleep.
Maddening Touch. Melee Spell Attack: +6 to hit, reach 5 ft., one target. hit: 17 (4d6+3) 4d6+3 psychic damage.
Howling Babble (Recharge 6). Each creature within 30 feet of the allip that can hear it must make a DC 14 Wisdom saving throw. One a failed save, a target takes 12 (2d8+3) 2d8+3 psychic damage, and it is stunned until the end of its next turn. On a successful save, it takes half as much damage and isn't stunned.
Whispers of Compulsion. The allip chooses up to three creatures it can see within 60 feet of it. Each target must succeed on a DC 14 Wisdom saving throw, or it takes 12 (2d8+3) 2d8+3 psychic damage and must use its reaction to make a melee weapon attack against one creature of the allip's choice that the allip can see.
Greatsword: Melee Weapon Attack: +6 to hit, reach 5 ft, one target.
Hit: 13 2d8+4 bludgeoning damage.