Doom

Lucifer the Doom is a melee strength Hero with strong farming capabilities and a flexible skill and item build. He has low starting armor, but his abilities and high health allow him to lane or even jungle quite effectively. A ruthless demon, he possesses malicious abilities revolving around greed, fire, and death. His Devour ability allows him to consume creeps, providing additional gold and allowing him to absorb any powers that creep had, which potentially allows him to have up to six total hero skills. Because there are numerous creep abilities to choose from, the role that he chooses to play is quite flexible. His other main abilities Scorched Earth and LVL? Death, provide him mobility/sustenance and spammable nuke, respectively. Finally, his namesake ult Doom serves as one of the strongest single target lockdown abilities in the game. A unit afflicted with Doom takes intense damage over a lengthy duration, while having all his active abilities - even those from items - completely silenced. With the ability to farm a lot of expensive items very quickly and the ability to render an enemy hero completely useless during a teamfight, Doom can quickly become a walking nightmare on the battlefield.

Tips

 * Doom has very poor Agility gain and one of the lowest starting armor in the game so it is essential to tank him up with armor items such as Assault Cuirass and Shiva's Guard to make his high HP go farther against physical attacks.
 * Be aware of heroes that commonly build Linken's Sphere as casting Doom on them will result in it being completely wasted. Cast LVL? Death on them first to burn the Linken's Sphere cooldown before casting Doom.
 * Cast Doom early in teamfights - the huge 15 second duration can render spell-dependent nukers such as Zeus or Lina virtually useless. Alternatively, if you can catch a hero carrying key support items like Mekansm and Pipe of Insight you can prevent those items from being used during the subsequent fight.
 * Make use of Devour's ability steal to give yourself and your team useful neutral creep auras like regeneration, swiftness or bonus damage. One of the best lategame option is a wolf pack leader with passive critical hit chance (20 % for 2x damage) and 30% bonus damage aura. A Satyr Trickster gives you a purge spell on a very low (5 seconds) cooldown, it is a very versatile skill and it's another strong choice. A Kobold Taskmaster's movement speed aura can also be useful for ganking, chasing and fleeing.

Trivia

 * Several of Doom's abilities are inspired by Final Fantasy's Blue Mages. LVL? Death was probably based off of the Level 5 Death skill. Devour is highly similar to Quina Quen's eat and cook abilities from Final Fantasy IX. His ultimate, Doom, also shares the same name of another Blue Mage ability,  but the mechanics differ.
 * His name, Lucifer, is the name of a fallen angel who is known as the Devil in the Bible.
 * Despite his ultimate being a regular pentacle, a pentagram or pentacle is actually a symbol of protection, and does not mean evil or anything of the like, despite its current connotations. Paganism has no devil or Satan-esque figure. The picture/ability, to hold any sort of "evil", should be inverted, and due to the fact it changes direction when used on an enemy, should probably hold the face of Baphomet, too.