Shadow Fiend is a ranged character. His primary attribute is agility. The hero is mainly taken as a midlaner. Most effective in the early and mid game.
Thanks to the Shadoraze ability, Shadow Fiend is able to dominate his lane from the first minute. This ability is also effective in fast farming neutral creeps. Presence of the Dark Lord helps the hero better deal with armored opponents or summoned creatures in a team fight. Necromastery allows the character to deal a lot of attack damage in the early game. Requiem of the Soul is capable of eliminating almost any enemy hero, which is very effective in team fights. Aghanim's Shard allows Shadow Fiend to improve the Necromastery ability, which will be very useful when choosing a physical damage build. Aghanim's Scepter will buff Requiem of the Soul, making it even more damaging and the hero more durable.
Over the ages Nevermore the Shadow Fiend has claimed the souls of poets, priests, emperors, beggars, slaves, philosophers, criminals, and heroes. Such is his evil, so intense his aura of darkness, that no rational mind may penetrate it. And if you really want to know where the stolen souls go, there's one sure way to find out: add your soul to his collection.