Doom

Lucifer the Doom Bringer is a melee strength Hero with strong farming and laning capabilities. He has low starting Armor, but his abilities and high health allow him to lane effectively even while being harassed. A ruthless and malicious demon, this terrifying monster possesses demonic powers revolving around evil and death and is a towering force that uses his lethal abilities to annihilate his adversaries. His Devour ability allows him to consume creeps, gaining any powers that creep had. He is quite capable of farming in the jungles for quick gold and creep powers to absorb. Doom has been feared by many, particularly Invoker, due to his ultimate, Doom, which is known to deal intense damage and silence any Hero rendering their abilities useless. Doom is an extremely dangerous hero due to his farming capabilities. If he gets buffed too much from items, he becomes 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.