Burning Attack, Emanation, Irresistible Attack

[Sunrunners_Fire]

Now this is a fun one:

Innate Attack (Burning) 10d

• Area Effect 15
• Cosmic: Irresistible Attack
• Wall: Permeable (Any Shape Desired)
• Emanation

Wall is preset to make the Area-Effect into a Spherical Area Effect, working out to a 28.63 yard radius sphere. This utterly ignores DR. It hits everything (except the user) within the Spherical Area Effect. That is the easy part.

The complex part: How do I calculate how much of the landscape is slagged? Cover, barriers, etc ... none of that matters. The ground can't hide behind the ground to avoid damage so long as it is within the Spherical Area Effect. It all gets slagged equally.

A 1/64 lb homogeous "object" (itty bits of the ground) is 2 HP. Minimum damage for 10d (assuming all 1s are rolled for damage) takes that down to -8 HP (or -HPx4 if you prefer). The expected 3.5 per dice (35 damage) reduces said object to -33 HP (-HPx16.5), utterly destroying it.

Is this the appropriate method of determining the effect?

(... for those of you who are going to ask the question of what this is meant to represent: a conversion suffusion-field that partially converts some of the affected matter into micro-quantities of anti-matter, then allows the more normal matter/anti-matter reactions to take place. The other expected effects of this mixing are constrained by "special" forces and methods.)