Multiattack

The dau makes two slam attacks.

Slam

Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 6 (1d6 + 3) bludgeoning damage plus 10 (3d6) necrotic damage, and the dau regains hit points equal to the necrotic damage dealt. The target must succeed on a DC 13 Constitution saving throw or its hit point maximum is reduced by an amount equal to the necrotic damage taken. This reduction lasts until the creature finishes a long rest.

Tangible Illusion (1/Day)

After casting an illusion spell of an object, the dau temporarily transforms that illusion into a physical, nonmagical object. The temporary object lasts 10 minutes, after which it reverts to being an illusion (or vanishes, if the duration of the original illusion expires). During that time, the illusion has all the physical properties of the object it represents, but not magical properties. The dau must touch the illusion to trigger this transformation, and the object can be no larger than 5 cubic feet.