Shadow Fiend build & guide (7.41)

Shadowraze

Shadow Fiend razes the ground directly in front of him, dealing damage to enemy units in the area, dealing bonus damage based on his current Necromastery Soul amount. Adds a stacking damage amplifier on the target that causes the enemy to take bonus Shadowraze damage per stack.

Aghanim's Shard: Cooldown reduced by 2s per enemy hero hit. Applies a stacking 12% movement speed debuff on enemies hit.

Feast of Souls

Shadow Fiend gains Bonus Movement and Attack Speed for 8 seconds. For the duration of the effect, every 0.5s he collects souls from 2 enemies in a 600 radius. After the effect is over, he loses the souls whose owners are still alive, retaining the rest for 8s, after which souls that are over the Necromastery max stack count are also lost. Can only collect souls once from each individual enemy.

Presence of the Dark Lord

Shadow Fiend's presence reduces the armor of nearby enemies.

Requiem of Souls

Shadow Fiend gathers up to 20 of his captured souls to release them as lines of demonic energy. Units near Shadow Fiend when the souls are released can be damaged by several lines of energy. Any unit damaged by Requiem of Souls will be feared and have its movement speed and magic resistance reduced for 0.6 seconds for each line hit up to a maximum of 2.15. Lines of energy are created for every soul captured through Necromastery. Requiem of Souls is automatically cast whenever Shadow Fiend dies, regardless of its cooldown.

Aghanim's Scepter: Reduces cooldown and causes Requiem of Souls to return back to Shadow Fiend. The wave back to Shadow Fiend heals him for all the damage it dealt.

Necromastery

Shadow Fiend steals the soul from units he kills, gaining 1 bonus damage per soul. Hero kills grant 4 souls. On death, he releases 30% of them from bondage.

Aghanim's Scepter: Increases max souls.