Spell that mixes transmutation and necromancy. Can be used in any room but only in room's.

Otherworldly song gives life to things that never was supposed to live - to walls of room for this spell. The bricks and planks in the walls do not change in appearance, but they acquire some of the characteristics of living beings - they feel pain, fear, and agony. The suffering tears apart their structure, and with a thunderous scream, the elements of the walls begin to crack and bleed. The amount of blood rapidly increases, filling the room with blood. The room's door and windows are also under a spell and cannot be opened. Within 10 minutes, the room is completely filled with blood.

This is an ancient forbidden spell used as a trap to kill a group of people by drowning them in blood.
The structure of walls, doors, and windows does not change along with their characteristics, so it is quite easy to escape from such a room by breaking the door or windows. However, this spell is most effective in prisons and dungeons, where escaping is much more difficult.