Circle of Death

Source circle of death

The number of Hit Dice worth of creatures killed by the spell increases to 1d6 per caster level (maximum 20d6). Add your tier to the maximum HD of creatures that can be affected by the spell. (For example, at 3rd tier, a creature with 12 HD cannot be affected.)

Augmented (6th): If you expend two uses of mythic power, creatures that succeed at their saves against this spell take 1d6 points of damage per tier.