||"The chaos flame is said to have devoured the mother of pyromancy.
Create multiple pillars of chaos flame.
Those who sought great power were consumed by their own desires.Where are these lost souls now?"
||Treasure at the end of a lava path in the Iron Keep
||The easiest way to safely retrive Chaos Storm without dying, is to coat yourself in water from the urns, found on the upper level leading to the roof, and then casting Flash Sweat*.
Doing so will reduce the damage to a point in which you can easily counter it with healing items and estus.
Wearing the Pharros Mask helps when it comes to walking along the lava paths. As the water effect the mask provides reduces fire damage.
Equipping armor with high fire defense and a Flame Quartz Ring will reduce the damage further and might be necessary if you have low base health.
Note: Keep in mind that Flash Sweat and Small Orange Burrs won't stack. Instead they will override the previous applied effect.
Video Walkthrough of getting to the chest without dying