Calamity Symphony (3.5e Maneuver)

Great, whirling coils of death surround you wherever you go, the sweet sound of their slicing the air providing a serenade of destruction.

While in this stance, your weapon adds 5 ft. to its reach, while maintaining the ability to strike adjacent squares. Further, any foe completely surrounded by squares you threaten (or with squares you threaten on three sides and you yourself on the fourth) is considered flanked for all attacks.

This ability does not function if they have a wall or similar on one or more sides, even if you would threaten those squares.