Doom

Lucifer, otherwise known as Doom, is a melee strength Hero with strong farming capabilities, good versatility, and one of the strongest single-target spells in the game. His very low starting armor makes him vulnerable to harassment, but his abilities and high health allow him to lane or even jungle quite effectively. As 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 abilities. Because there are numerous neutral creep abilities to choose from to supplement his other abilities, the role that he chooses to play is quite flexible. Scorched Earth serves numerous purposes, allowing him to chase, escape, regenerate, and slowly burn his enemies all at once. LVL? Death is a spammable nuke that does either modest or massive damage to the enemy, depending on the enemy's level. 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 numerous expensive items in his arsenal and a key enemy hero rendered useless for a teamfight, a farmed Doom ensures that nobody can extinguish his flame.

Tips

 * Doom has very poor Agility gain and one of the lowest starting armor in the game so it is often 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.
 * Always make sure to never max out LVL? Death, but instead level it when your enemies are in multiples of 6,5,4, and 3 in order to make it hit as hard as possible.
 * Necronomicon is a very strong item on Doom, since Scorched Earth will heal your summons as well. The item also gives Doom valuable intelligence.
 * Unlike other melee heroes, Doom has 150 attack range (while the normal melee hero has 128 attack range)
 * With an Aghanim's Scepter, the potential total damage your ultimate can deal is practically infinite assuming that the target cannot distance himself 900 units away from Doom for 16 seconds. You can kill enemy heroes that is particularly hard to shut down by just chasing them while they are Doomed. Items such as Sange and Yasha, Eye of Skadi, Shiva's Guard and other movement granting items would make Doom able to chase particularly well when combined with Scorched Earth.
 * Due to the recent changes to Doom's ultimate, Aghanim's Scepter is now practically a core item because it is needed to disable passive abilities of enemy heroes. Without it, you will find heroes such as Faceless Void or Phantom Assassin incredibly hard to shut down.
 * 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.
 * Remember that Doom disables passives when upgraded with an Aghanim's Scepter, If there is enemy heroes such as Phantom Assassin, Faceless Void, Huskar or Lifestealer in the enemy team that rely on their strong passives to deal damage, do not hesitate to use it on them to remove their fighting capabilities especially if they're the only one the enemy team who has the capability to carry.
 * Make use of Devour's ability steal to give yourself and your team useful neutral creep abilities like stuns, slows, ensnares, or different types of auras.
 * Dark Troll Summoner is one of the best creeps to devour for a jungling Doom in early game. It gives Raise Dead, allowing you to summon two skeleton warriors who can tank creeps for you.
 * Another useful creep for jungling is Satyr Tormenter, its Unholy Aura provides great health regeneration (4 health/second), and can also be used while laning to help you and allies hold lane longer. The Shockwave nuke has a high mana cost, but has good range and moderate cooldown, which you can use to finish off fleeing enemies with low health. In the early stages of the game, it can also be used to effectively harass your opponents in-lane.
 * Satyr Mindstealer's Mana Burn could be used to prevent heroes with small mana pool such as Sven or Chaos Knight from attempting an early kill. It could also be used against lane supports to prevent them from assisting their carries.
 * Hill Troll Priest's heal and mana regeneration aura are good for laning as well. The low mana cost healing spell can be useful against heroes who deal damage over time like Venomancer, Viper, or Axe, and is particularly useful against Silencers Curse of the Silent.
 * In midgame, you may opt for more powerful spells such as War Stomp (from Centaur Conqueror), or Ensnare (Dark Troll Summoner). A Satyr Trickster gives you a Purge spell on a very low (5 seconds) cooldown, it is a very versatile ability and is another strong choice. Remember that it has a short cast range of 350.
 * In lategame, one of the best options is an Alpha Wolf with passive critical hit chance (20% for 2x damage) and 30% bonus damage aura.
 * This synergizes with aura items such as Vladimir's Offering and Assault Cuirass giving your whole team a huge advantage.
 * A Kobold Foreman's movement speed aura can also be useful for pushing, ganking, chasing and fleeing.
 * Doom is a very versatile hero capable of assuming different roles, sometimes even at the same time, due to his ability to farm well (especially with a Hand of Midas) and ability to gain different neutral creep skills enabling him to build certain items and combinations thereof to suit what your team needs.
 * as a Tank with defense items such as Vanguard, Heart of Tarrasque, and Shiva's Guard.
 * as a Semi-Support with aura and team-oriented items such as Crimson Guard, Arcane Boots, Mekansm, Pipe of Insight, Vladimir's Offering and Drums of Endurance, although some players believe playing Doom as a Utility/Support is a waste of his potential.
 * He can also buy courier and wards if the situation calls for it, and it won't hurt his farm as much as carries.
 * During laning phase, skills such as Hill Troll Priest's heal or Unholy Aura could be used to babysit other carries.
 * as a Ganker with items such as Shadow Blade or Blink Dagger.
 * He could also use this in conjunction with War Stomp to initiate.
 * as a Disabler with a Refresher Orb and an Aghanim's Scepter or even a Scythe of Vyse.
 * Purge, War Stomp, or Ensnare could also help your team-mates secure a kill.
 * as a Hard-Carry with an Abyssal Blade and/or Mjollnir, although this is inadvisable if he is the only carry in the team because he will be outcarried by other carry heroes such as Phantom Assassin, Anti-Mage etc.
 * Doom however enables a team to have a huge gold advantage because he can farm items without interfering with your team-mate's farm.

Trivia

 * Several of Doom's abilities are inspired by Final Fantasy's Blue Mages. LVL? Death was based off of the Level 5 Death ability and the mechanics of a LVL? S-flare. Devour is highly similar to Quina Quen's eat and cook ability 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 taken from the Bible's Book of Isaiah and translates roughly to "morning star". It is often used to refer to the Biblical Devil (or Satan), thus fitting Doom's evil and demonic image.
 * Doom's ultimate icon depicts a pentacle which, despite its popular connotation as Satanic/"evil" mark, is actually a Pagan symbol of protection. For its common "evil" symbolism to apply, the pentagram has to be inverted; this only occasionally occurs in-game, as the "star" inside the circle of the ability's particle effect slowly rotates.
 * One of his responses upon acquiring the Invisibility rune (" doom_invis_03.mp3 Heheheh, see no evil.") refers to the and their associated phrase: "See no evil, hear no evil, speak no evil."
 * His ultimate and signature ability, Doom, derived from the ultimate of the Pit Lord, a playable hero in Warcraft III: Frozen Throne. The original ability varied in that it was only castable on non-hero units, is non-removable until death, and upon the target unit's death, it would spawn a Doomguard. The Doomguard's model was Lucifer's hero model in DotA.