Fiend Deck

Dark Necrofear Deck
This build centers on the summoning of the monster Dark Necrofear, released in Labyrinth of Nightmare and reprinted in Dark Beginning 2. Boasting a pretty high 2200 ATK and a powerful 2800 DEF, this monster's special ability is what makes it special. Capable of stealing an opponent's monster when it's destroyed by equipping to the selected target as an Equip Spell Card (just like Snatch Steal but without the Life Point gain to your Opponents (GX1-VG)) makes Dark Necrofear very hard to get rid of. Most of these decks use Newdoria and Fires of Doomsday to maintain field presence and gather Fiends in the Graveyard. Kuriboh can also be used to gather Fiends in the Graveyard to summon Necrofear and because of the summoning cost of this card (removing 3 Fiend-Type monsters in your Graveyard from play), many players use it in conjunction with Dimension Fusion and Return from the Different Dimension to summon every removed monster and attack for game. With Solidarity making all Fiend-Type monsters get 800 ATK more, and Dark Necrofear will have 3000 ATK.

Dark/Fiend Deck
This deck fuses fiends with cards for dark monsters, like Escape from the Dark Dimension, Allure of Darkness or Eradicator Epidemic Virus. The cemetery must be have a constant supply for Dark Necrofear, The Beginning of the End and at least 1 monster for Solidarity. You can use Veil of Darkness to achieve this. Dark Fiends have a great support for tokens created with Phantom Skyblaster or Fires of Doomsday, so you can use this to use Hate Buster, Pot of Avarice, and Raviel, Lord of Phantasms.

Monsters

 * Archfiend Soldier
 * Card Guard
 * Dark Hunter
 * Dark Necrofear
 * Darkness Neosphere
 * Dark Resonator
 * Dark Ruler Ha Des
 * Djinn Presider of Rituals
 * Doomcaliber Knight
 * Doomsday Horror
 * Goblin King
 * Grave Squirmer
 * Legendary Fiend
 * Mad Archfiend
 * Mask of Darkness
 * Mist Archfiend
 * Night Assailant
 * Newdoria
 * Phantom Skyblaster
 * Raviel, Lord of Phantasms
 * Snipe Hunter
 * Tragoedia
 * Vanity's Fiend
 * Yubel
 * Yubel - Terror Incarnate
 * Yubel - The Ultimate Nightmare
 * The Wicked Avatar

Spells

 * The Beginning of the End
 * Veil of Darkness
 * Allure of Darkness
 * Solidarity
 * Smashing Ground
 * Fires of Doomsday
 * Creature Swap
 * Pot of Avarice

Traps

 * Magic Drain
 * Hate Buster
 * Eradicator Epidemic Virus
 * Soul Demolition
 * Deck Devastation Virus
 * Escape from the Dark Dimension
 * Dark Illusion
 * Dust Tornado

Extra Deck

 * Phantasm Token
 * Skyblaster Token
 * Doomsday Token
 * Guard Counter

Archfiend Deck
These decks use the Archfiend monster family which was released in Dark Crisis and reprinted in Dark Revelation 1. Archfiends are fast monsters with a lot of powerful Level 4 attackers like Archfiend Soldier and Shadowknight Archfiend. Terrorking Archfiend is a powerful monster with only 4 stars that is capable of negating the effects of any monster it destroys. Its only drawback is its summoning requirement (having an Archfiend monster card face-up on your side of the field in order to Normal Summon or Flip Summon this card). Archfiend monsters have 2 effects in common:
 * You must pay a certain amount of Life Points to keep them on the Field. This cost is not optional, and you must pay if possible. If you run out of Life Points, Archfiend monsters are destroyed immediately.
 * The controller of an Archfiend monster card can roll a six-sided die when that monster is targeted by an effect. Each monster states a (number of) result(s), and if the die provides that result the targeting effect is negated and the targeting card is destroyed.

The Life Point cost is the main weakness of this deck. Pandemonium is a Field Spell Card that prevents both players from paying the Life Point cost (and allows to a player whose Archfiend monster is destroyed to search his/her deck for another Archfiend monster with a lower level than the destroyed one and add it to his/her hand). Because Archfiend Decks rely on Pandemonium to avoid losing due to its own costs, players tend to avoid this type of build.

Some newer Archfiend monsters are not made for the archetype but are in it because their names are demonic and are softened due to laws in the United States.

Monsters

 * Raviel, Lord of Phantasms
 * Shadowknight Archfiend
 * Terrorking Archfiend
 * Skull Archfiend of Lightning
 * Archfiend General
 * Imprisoned Queen Archfiend
 * Pandemonium Watchbear
 * Inferno Hammer
 * Archfiend Soldier
 * Mist Archfiend
 * Dark Necrofear
 * Archfiend of Gilfer
 * Cyber Dragon
 * Darkbishop Archfiend
 * Sinister Serpent
 * Warrior of Zera
 * Mazera DeVille
 * Dark Ruler Ha Des
 * Kuriboh
 * Mad Archfiend
 * Dark Resonator
 * Dark Tinker
 * Evil Hero Infernal Gainer
 * Infernalqueen Archfiend
 * Legendary Fiend
 * Caius the Shadow Monarch
 * Prime Material Dragon
 * Red Dragon Archfiend
 * Red Nova Dragon
 * Majestic Red Dragon

Spells

 * Checkmate
 * Dark Designator
 * Field Barrier
 * Falling Down
 * Heart of Clear Water
 * D.D. Designator
 * Hammer Shot
 * Pandemonium
 * Archfiend's Oath
 * Convulsion of Nature
 * The Puppet Magic of Dark Ruler
 * Axe of Despair
 * Gravekeeper's Servant
 * Reload
 * D.D.R. - Different Dimension Reincarnation

Traps

 * Sakuretsu Armor
 * Battle-Scarred
 * Curse of Anubis
 * Nightmare Wheel
 * Hate Buster
 * Final Attack Orders
 * Nightmare Archfiends
 * Prideful Roar
 * Solemn Wishes
 * Dark Illusion

Synchros

 * Red Dragon Archfiend
 * Thought Ruler Archfiend
 * Chaos King Archfiend

Dark World Deck
This Deck type centers on the use of Dark World monsters, introduced in Elemental Energy, to dominate the field by using cards with discarding effects, like Morphing Jar, Card Destruction and Dark World Lightning, or by forcing the opponent to discard cards from the user's hand by effects like Dark Deal or Dragged Down into the Grave (a well-known combo is to give your opponent your face-down Morphing Jar with Creature Swap and then attacking it to trigger the Jar's effect and cause a discard "by your opponent's card effect", which is very bad news for the player not using Dark World). A Dark World build is fast, and can occupy the 5 monster card slots very quickly, but that causes a very small hand size. Card of Safe Return and Broww, Huntsman of Dark World are used to prevent that, as well as Morphing Jar. Dark World monsters that are discarded by your opponent's effect often gain extra effects, making cards like Dark Deal a lot more useful. Another good Idea with this deck is to use Darknight Parshath. Since you are constantly discarding monster cards and most of the discarded monster cards are DARK, Parshath will gain 100 ATK for each one. If you have Mystic Plasma Zone on the field it gives DARK monsters a 500 ATK boost and if you have at least 6 DARK monsters in the graveyard, Parshath becomes a single tribute 3000+ ATK monster.

Monsters

 * Zure, Knight of Dark World
 * Renge, Gatekeeper of Dark World
 * Kahkki, Guerilla of Dark World
 * Gren, Tactician of Dark World
 * Scarr, Scout of Dark World
 * Beiige, Vanguard of Dark World
 * Broww, Huntsman of Dark World
 * Brron, Mad King of Dark World
 * Sillva, Warlord of Dark World
 * Goldd, Wu-Lord of Dark World
 * Reign-Beaux, Overlord of Dark World
 * Night Assailant
 * Morphing Jar
 * Raviel, Lord of Phantasms
 * Great Maju Garzett
 * Goblin King
 * Doom Shaman
 * Dark Necrofear
 * Darknight Parshath
 * Dark Resonator
 * Dark Ruler Ha Des
 * Gorz the Emissary of Darkness
 * Legendary Fiend
 * Darkness Neosphere
 * Snipe Hunter

Spells

 * Dark World Dealings
 * Gateway to Dark World
 * Dark World Grimoire
 * Dark World Lightning
 * Mystic Plasma Zone
 * Dark Designator
 * The Cheerful Coffin
 * Swords of Concealing Light
 * The Puppet Magic of Dark Ruler
 * Card Destruction

Traps

 * Dark Deal
 * The Forces of Darkness
 * Fine

Synchros

 * Stardust Dragon
 * Red Dragon Archfiend
 * Brionac, Dragon of the Ice Barrier
 * Dark Highlander

Monsters

 * Raviel, Lord of Phantasms
 * Yubels
 * Sangan
 * Dark Crusader
 * Earthbound Immortal Ccapac Apu
 * Archfiend Soldier
 * Mystic Tomato
 * Giant Orc
 * Goblin King
 * Grinder Golem
 * Evil Hero Infernal Gainer
 * Mask of Darkness
 * Wall of Illusion
 * Doom Shaman
 * Familiar Knight
 * Dark Ruler Ha Des
 * Darkness Neosphere
 * Beiige, Vanguard of Dark World
 * Sillva, Warlord of Dark World
 * Zure, Knight of Dark World
 * Newdoria
 * The Bistro Butcher

Spells

 * Lightning Vortex
 * Tribute to the Doomed
 * Smashing Ground
 * Magical Mallet
 * Dragged Down into the Grave
 * Sword of Dark Destruction
 * Black Pendant
 * Inferno Tempest

Traps

 * Scrap-Iron Scarecrow
 * Cemetery Bomb
 * Hate Buster
 * Magic Cylinder
 * Trap Hole
 * Shadow Spell
 * Spellbinding Circle
 * Metalmorph
 * Trap Jammer
 * Return from the Different Dimension