The Shroud/Prismatic Wall

The Prismatic wall is a constantly moving vertical, opaque wall—a shimmering, multicolored plane of light that will instantly kill you if your allow it to touch you.

Currently the only one in the game is found in The Shroud, in phase 3. There is no way to survive it except by running away, or using the cleric capstone - Divine intervention.

How to defeat the wall:
 * Either complete all the puzzles, then fill the water fountains. or
 * Skip the puzzles and fill the waters without completing them. Doing it this way may be faster in some groups, but you will lose a treasure chest in the process, so it's not recommended.

A Prismatic Wall As Seen By A WotC Artist:

http://i44.tinypic.com/2nvxbhk.jpg