An immobile, blazing curtain of shimmering violet fire springs into existence. One side of the wall, selected by the character, sends forth waves of heat, dealing 2d4 points of fire damage to creatures within 10 feet and 1d4 points of fire damage to those past 10 feet but within 20 feet. The wall deals this damage when it appears and each round that a creature enters or remains in the area. In addition, the wall deals 2d6 points of fire damage +1 point of fire damage per caster level (maximum +20) to any creature passing through it. The wall deals double damage to undead creatures.
If the character evokes the wall so that it appears where creatures are, each creature takes damage as if passing through the wall. Each such creature can avoid the wall by making a successful Reflex save. (If the creature ends up on the hot side of the wall, it takes 2d4 points of damage, as normal.)
If any 5-foot length of wall takes 20 points of cold damage or more in 1 round, that length goes out. (Do not divide cold damage by 4, as normal for objects.)