This passive is now a reverse execute mechanic, and increases your damage against targets by 1% for every 10% health they currently have.
The minimum bonus this passive can provide is 1% increased damage done.
Developer Comment: This change was aimed at helping Sorcerer's damage production go up, while helping them in the targeted gameplay pattern of getting targets into specific health thresholds, detracting from the feeling of uncontrollable burst for the caster, and sudden moments of low telegraphed high damage for the target.