Blank

Incorporeal Movement. The blank can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object

Harmed by Water. The Blank takes 20 acid damage when it ends its turn in water or if its splashed by at least 10 gallons of water.

Stunned By Electricity: The Blank must make a con save dc equal half the damage taken (or 10 whichever is higher) if the damages type is lightning or be stunned.

Destroyed by fire: The only way to permanently kill a blank is with fire.

Face Stealer: The Blank will attempt to steal the exposed face of a large or smaller creature within range (5ft) said creature must make a DC: 14 Dex saving throw or loose its face.

A creature that looses its face is blinded and star to suffocate unless they take at least 4 slashing or piercing damage to reopen an airway. A face can only be fixed by destroying the blank that stole the face and burning the old face and casting lesser restoration, greater restoration, regenerate or wish. A face can be removed from a blank up until the 24 hour mark. After this the face is permanently attached to the blank and it starts developing.