Deadly Doorway

When you cast this spell, you touch a doorway, gate, window, or other construction that serves as an opening between two locations. You can speak a word, phrase, or describe an action or activity that must be performed to secure safe passage through the door. The first creature that does not perform this safeguard while passing through the doorway must succeed a Charisma saving throw or take [roll]5d10[/roll] necrotic damage and be paralyzed until the start of their next turn. A creature slain by this damage withers into dust, leaving all their clothing and possessions behind.