User:R. New Beta/Fiend Deck

Monsters (23)
Dark Necrofear x2

Dark Ruler Ha Des

Lava Golem

The Masked Beast

Gren Maju Da Eiza x3

Witch's Apprentice

Goblin King

Mystic Tomato x3

Manju of the Ten Thousand Hands

Sonic Bird

Opticlops

La Jinn the Mystical Genie of the Lamp

Big Eye

Mystic Clown x3

Grand Tiki Elder

Dark Elf

Spells (14)
Curse of the Masked Beast

The Cheerful Coffin

Soul Release x2

Mask of the Accursed

Yami

Mystic Plasma Zone

Dark Energy x2

Sword of Dark Destruction

Heavy Storm

Lightning Vortex

Swords of Revealing Light

Soul Absorption

Traps (7)
Deck Devastation Virus

Ultimate Offering

Magic Cylinder

Dust Tornado

Jar of Greed

Magic Jammer

Trap Jammer

TOTAL: 44

Workings

 * Dark Necrofear is there because of its control effect, and because it removes monsters from play (more on that later)


 * Dark Ruler Ha Des is there because it's a Fiend deck, so his effect is useful here


 * Lava Golem equipped with Mask of the Accursed inflicts 1500 damage to your opponent every turn


 * The Masked Beast is a general powerful attacker


 * Gren Maju Da Eiza is the trump card. When you've removed from play as many cards as this deck allows (16) with the effects of Dark Necrofear and Soul Release, it has a whopping 6400 ATK and DEF


 * Witch's Apprentice is there to give the other monsters a power boost


 * Goblin King can have a maximum of 4000 ATK here


 * Mystic Tomato is for summoning Tribute fodder, and also to be removed from play after it's been destroyed


 * The other monsters are there as Tribute fodder for Dark Necrofear, The Masked Beast, and Dark Ruler Ha Des, and also to be removed from play with Soul Release. Dark Elf is for Deck Devastation Virus. Opticlops and La Jinn can also be used as basic attackers.


 * Curse of the Masked Beast is there to summon The Masked Beast, obviously


 * The Cheerful Coffin gets the three Tributes for a Dark Necrofear into the Graveyard quickly


 * Soul Release powers Gren Maju Da Eiza up by 2000 points, and there are two of it


 * Mask of the Accursed helps with Lava Golem, as explained above


 * Yami, Mystic Plasma Zone, Dark Energy, and Sword of Dark Destruction give power-ups


 * Heavy Storm, Lightning Vortex and Swords of Revealing Light are just useful to have around


 * Soul Absorption is a great card in this deck, as it increases your LP by 500 when a monster is removed from play, which happens a lot


 * Deck Devastation Virus is coupled with Dark Elf, and destroys monsters with <1500 ATK, which could make it harder for your opponent to tribute summon


 * The rest are just good and some can protect your monsters in various ways.


 * And there's this really clever thing: Normal Summon Manju from your hand and use his effect to pull The Masked Beast from your Deck. Then activate Ultimate Offering, paying 500 Life Points to Normal Summon Sonic Bird from your hand, then use its effect to pull Curse of the Masked Beast from your Deck. Then activate Curse of the Masked Beast, Tribute Manju and Sonic Bird and Ritual Summon the Masked Beast.