Entropy

Your spells gain a 12% chance per rank (up to 36%) on hit to inflict Festering Plague — a stacking INT-scaling shadow rot (up to 4 stacks).

Your rots feed your reserves — each tick of your decay has a 10% chance per rank (up to 30%) to draw mana from the withering foe.

When you kill a foe, Festering Plague erupts to the nearest enemy within 700 range at triple virulence (3 stacks) — packs fall like dominoes.

Necrotic Decay becomes Entropy Cascade — each tick has a 30% chance to spread the rot to a nearby enemy, turning a single dot into a spreading plague across the pack.

Dread becomes Unnerving Terror — a fear that leaves a lingering rot after the target breaks, adding one more disease to the pile.

Essence Siphon becomes Soul Harvest — an AoE drain channel that withers every foe around you, feeding the cascade.

Grasp of the Grave becomes Wretched Pull — a damage-focused grasp that roots its victim for 3 seconds so your rots run their full course.

CAPSTONE — detonate a withering foe's soul: heavy death damage to everything nearby PLUS a burst that detonates the target's Festering Plague (scaling with its stacks), and a virulent Collapsing Decay lingers on the survivors.