Tycho’s longevity

A wave a great magical energy emits from the point of the casters focus. Any creatures inside the 120ft radius makes an INT save (DC of the caster). Taking 20d12+40 force damage, half as much on a save. Any living creature slain by this spell grants the caster an additional year of life. If a target is reduced to -10hp by the spell they turn to dust and disintegrate. 

Spell deals damage to constructs, undead and objects. Only living creatures grant longevity to life.