As an action, consumptive energy ripples out from you. Each creature other than you in a sphere centered on you must make a Reflex saving throw. If the creature is a construct or an undead, the spell has no effect on it.
On a failure, it takes 2d8 necrotic damage.
On a critical failure, it takes twice as much damage.
On a success, it takes half as much damage.
On a critical success, it takes no damage.
You regain health equal to half the amount of necrotic damage dealt.
You can increase the damage by 1d8 for each additional mana expended.
You can expend 1 additional mana so the death field around you is continuous. The duration changes to 1 minute/mana, concentration and the death field remains around you in an aura shaped as a sphere. Until the spell ends, the aura moves with you, centered on you.
Whenever a creature enters the area for the first time on a turn or starts its turn there, it must make the Fortitude saving throw. The damage is reduced to 2d4 and additional augments to the damage increase the damage by 1d4 for every two additional mana expended, instead of the normal increase.