This deck is a complete beatdown deck mainly focusing on "Malefic" monsters as well as Tragoedia and Gorz, the Emissary of Darkness, as easy beatsticks.
Deck: (40)
Monsters: (16)
The monsters are pure beaters, all level 7 or higher but easy to summon, using what I believe to be the best and most reliable and easy to summon "Malefics". "Gorz" and "Tragoedia" are making sure I never have an open field, and for extra beatsticks. Rainbow Dragon cannot be summoned in this deck, but is used as fodder for "Malefic Rainbow Dragon".
Malefic Cyber End Dragon x3
Malefic Stardust Dragon x3
Malefic Rainbow Dragon x3
Rainbow Dragon x3
Tragoedia x2
Gorz, the Emissary of Darkness x1
Malefic Truth Dragon x1
Spells: (16)
The spells are mainly to speed up and preserve "Malefic World" and clear the field at the same time.
Malefic World x3
Terraforming x3
Gold Sarcophagus x2
Demise of the Land x1
Field Barrier x1
Lightning Vortex x1
Dark Hole x1
Shield Crush x3
Heavy Storm x1
Traps: (8)
My main trap card is "Skill Drain". This is to negate the self-harming effects of my "Malefic" monsters, and can be a substitute for "Malefic World". You could also use "Royal Decree" to stop traps, but this cancels out "Skill Drain". Because my monsters all have massive ATK (with a potential exception of "Tragoedia", depending on the number of cards in my hand), "Deck Devastation Virus" is used to lock down all of my opponent's monsters and look at their cards and find a counter attack. I also used 3 "Metal Reflect Slime" in case I'm not getting any monsters and need to stall.
Skill Drain x3
Metal Reflect Slime x3
Deck Devastation Virus x2
Disclaimer: I don't have a lot of these cards, this isn't a real deck, but I thought it was a good idea. (Just for funzies)