Deep

"Deep" ( Shin'en) is an attribute currently unique to Darkness Dragon World. At first, this attribute was just typically added to cards with seemingly no purpose, but starting in Booster Set 5: Break to the Future, this became a supported attribute. The primary play style seems to be tearing down (or flat out ignoring) the opponent's defenses, while reinforcing your own defenses.

List of Sets containing Deep cards

 * Booster Set 4: Darkness Fable
 * Booster Set 5: Break to the Future
 * D Booster Set 1: Unleash! Impact Dragon!!
 * D Booster Set 2: Roar! Invincible Dragon!!
 * D Extra Booster 1: Buddyfight Collection
 * H Booster Set 4: Mikado Evolution
 * H Extra Booster 1: Miracle Impack!
 * H Extra Booster 3: Lord of Hundred Thunders
 * H Perfect Pack 1: Terror of the Inverse Omni Lords
 * Perfect Pack 1: Golden Buddy Pack (ver.E)
 * Trial Deck 6: Dark Pulse

Items

 * Blade of Lament, Sadgrieve
 * Purgatory Sword, Silver Givson (Legend/Darkness Dragon)
 * Evil Death Scythe
 * Sickle of Revenge, Avenger

Spells

 * Ability Shift
 * Absolute Attack
 * Abyss Symphony
 * Accel End
 * Apocalypse Death Shield
 * Black Armor
 * Bloody Dance
 * Dark Fog
 * Deadly Boost
 * Death Astray
 * Death Gauge Timer
 * Death Hiding
 * Devil Stigma
 * Guillotine Cutter
 * Hundred Demons Sorcery, Bad Trap
 * Inferno Rule
 * Lunatic
 * Million Edge
 * Redupsion Blood

Impacts

 * Brutal Disaster!
 * Dark Interment, Over the Grudge
 * Nightmare Despair

Size 2

 * Daredevil, "Soul Crusher"
 * Gallows, "Bloodsucker!"
 * Gratos, "Destruction Blade!"

Size 3

 * Daredevil, "Return"
 * Daredevil, "Salamander Dragon"

Size 0

 * Black Star, Cius
 * Black Swamp, Fen
 * Black Wolf, Ulbha
 * Caster of Forbidden Techniques, Velgaren
 * Death Ruler, Gallows "SD"
 * Death Ruler, Gespenst
 * Gate Guider, Gainare
 * Gate Guider, Stiju
 * Rhino Jailer, Headhunter
 * Shooter of Magic Bullets, Gaspard

Size 1

 * Black Dragon, Needle Fang
 * Black Dragon, Spinechiller
 * Black Knight, Hell Rapier
 * Black Superior Strength, Goradori
 * Daredevil, "Twister"
 * Daredevil, "Barrett"
 * Death Dragon, Deathgaze Dragon
 * Death Ruler Daredevil
 * Death Ruler, Alea
 * Death Ruler, Atihima
 * Death Ruler, Averia
 * Death Ruler, Burial
 * Death Ruler, Cremation
 * Death Ruler, Deathcusion
 * Death Ruler, Gallows
 * Deathgaze Dragon "SD"
 * Fourth Knight of the Apocalypse, Thanatos
 * Gate Guider, Andino
 * Gate Guider, De Lomeer
 * Gate Guider, Phlegethon
 * Gate Guider, Gallows "Gestus"
 * Gate Guider, Limbo
 * Hand of Muramasa, Katsukiyo
 * Infectious Malevolence, Yuberium
 * Rebellious Subject, Bellzelgard
 * Second Knight of the Apocalypse, Voremos
 * Third Knight of the Apocalypse, Aberrucia
 * Thousand Limbed Jailer, Cadval
 * Undying Skull, Sol Darion
 * Unfulfilled Desire, Greedy Beak

Size 2

 * Black Companion, Bephegol
 * Black Dragon, Death Hang
 * Black Knight, Goldred
 * Bloody Moon Dragon
 * Enshrouding All in Darkness, Gafner
 * Death Ruler, Abriel
 * Death Ruler, Blixt
 * Death Ruler, Executei
 * Death Ruler, Gruen
 * Death Ruler, Mastermind
 * Death Ruler, Pain
 * Death Ruler, Skull
 * Death Ruler, Soulbreaker
 * Death Ruler, Vroukalakas
 * Demon Swordsman, Deathstorm
 * Extreme Prison, Zwinger
 * First Knight of the Apocalypse, Gratos
 * Gate Guider, Malebolge
 * Void Omni Wicked Lord, Negulbalz

Size 3

 * Black Dragon of Demise, Death Tallica
 * Black Dragon, Dientes
 * Black-eye Demonic Dragon, Blagg Za Bath
 * Captive of Eternity, Zamseed
 * Death Ruler, Curse
 * Death Ruler, Thirteen
 * Divine Demon Slayer, Amenoohabari
 * Emissary of Ruin, Megiddo Death Tallica
 * Faceless Black Dragon, Laysface
 * Final Gate Guider, Giudecca
 * Grandmaster of the Apocalypse Knights, Gratos
 * Graveyard of Demonic Swords, Graybard
 * Hundred Demons General, Gokumengaiou
 * Master of Demise Executioners, Last Emperor

List of Support Cards

 * Black Dragon of Demise, Death Tallica
 * Bloody Dance
 * Brutal Disaster!
 * Hand of Muramasa, Katsukiyo