Iron chain

"Iron Chain", known as "Chain" (Ｃ(チェーン) Chēn) in the OCG, is an all-Earth archetype from Yu-Gi-Oh! 5D's used by Mr. Armstrong, included in the Crossroads of Chaos Booster.

"Iron Chain" cards focus upon a combination of milling the opponent's Deck, manipulating the ATK and DEF of monsters on the field, and inflicting minor burn damage to the opponent. A Deck dedicated to "Iron Chain" monsters can be relatively flexible because of this. The user can opt to stall the opponent with cards like "Gravity Bind", and use either "Poison Chain" to quickly make the opponent run out of cards, or "Iron Chain Repairman" to constantly recycle "Iron Chain Blaster" to burn the opponent each turn. Both can be used at once, and can be further devastating when combined with "Cemetary Bomb". The user can also go for a beatdown strategy by taking advantage of how "Iron Chain Coil" can increase the ATK and DEF of an "Iron Chain" card permanently, as well as how "Iron Chain Dragon" can temporarily increase its own ATK.

Most "Iron Chain" monsters are not very strong on their own. Without a card that can protect them during battle (e.g. "Scrap-Iron Scarecrow") or increase their ATK (e.g. "Gaia Power"), most cannot survive long - at least, not until "Iron Chain Coil" increases their ATK after a few turns. Since the archetype is not fully dedicated to a single method of defeating the opponent, it may not be as easy to control as other Archetypes, unless the user has a very good idea of what these cards are capable of as a group and what external support works well with their intended strategy.

Playing style

"Iron Chains" are most basically used as a Mill Deck; however they can be used in a Burn Deck with "Iron Chain Blaster" and "Paralyzing Chain". "Iron Chain Repairman" is useful for bringing back "Iron Chain" monsters from the Graveyard. This is useful, as "Poison Chain" needs "Iron Chain" monsters on the field to work. When used well, "Iron Chain" Decks can quickly achieve a Deck Out.

By using multiple copies of "Iron Chain Snake" on a high-Level monster, you will mill nearly (if not more than) half of your opponent's Deck.

The "Iron Chains" have their own Synchro Monster, "Iron Chain Dragon". Its effect sends the top three cards of your opponent's Deck to the Graveyard when it inflicts Battle Damage. Its other effect lets it banish all "Iron Chain" monsters in the Graveyard to have it gain 200 ATK for each.

Although a few Decks prefer cards in their Graveyard for effects, uncontrolled milling is different, causing those Decks to destabilize. The Teleport Dark Armed Deck requires exactly 3 DARK monsters in the Graveyard to Summon "Dark Armed Dragon", and adding more monsters adds a step to the Deck's key Summon. "Lightsworn" Decks already mill themselves, so adding on to that should only damage them further. Zombie Decks may lose a few key Spell/Trap Cards when discarding cards.

This Deck has easy access to a Level 7 Synchro Monster by using "Foolish Burial" or "Dust Knight" to dump a "Iron Chain Coil" into the grave, searching "Iron Chain Repairman" with "Reinforcement of the Army", and then using it to revive "Iron Chain Coil" to Synchro Summon.

This Deck can make use of of many Continuous Spells and Traps, such as "Gravity Bind", and "Level Limit - Area B", as an addition to "Poison Chain" and "Paralyzing Chain". "Hamon, Lord of Striking Thunder" and "Uria, Lord of Searing Flames" may be good additions to the Deck.

If you are using your "Iron Chain" Deck as a Stall Deck, then "Blood Mephist", "Gravity Bind", and "Stardust Dragon" are great cards to have in your Deck.

Using this Deck, one can easily get out "Iron Chain Dragon" without having to lose some monsters, specifically by tuning "Iron Chain Coil" with "Iron Chain Snake", then using "Iron Chain Repairman" to bring them back from the Graveyard.

This Deck may also be good against Exodia Decks, since it is sure to eliminate pieces of Exodia, which may be hard for the opponent to get back.

For those planning a beatdown, it is a good idea to run cards such as "Marshmallon" and "Marshmallon Glasses", and bulking up "Iron Chain Repairman" with "Iron Chain Coil" every turn.

If you watch carefully, you may see a strong milled card. You can then use "Monster Reborn" if it is a monster, or "Graverobber" if it is a Spell or Trap.

Signer Dragon Deck

If you were to use a Field Spell Card along with the Trap Card "Skull Invitation" you can use both "Ancient Fairy Dragon" and "Black-Winged Dragon" along with the other Signer Dragons. As a result, this Deck would be capable of using the Signer Dragons with ease.

Ancient Fairy Dragon - Supports Field Spells (3 recommended)
Black Rose Dragon - Destroys all cards on the field and sends them to the Graveyard, fueling "Cemetery Bomb".
Black-Winged Dragon - Protection from the effect damage caused by "Skull Invitation".
Red Dragon Archfiend- Can help "Iron Chain Dragon" cause effect damage.
Stardust Dragon - Protects cards from being destroyed before they are needed.

Also, "Black Rose Dragon" and "Ancient Fairy Dragon" can easily be Summoned by having "Iron Chain Repairman" Special Summon "Iron Chain Coil" from the Graveyard.

Overall, the Signer Dragons would work very well in an Iron Chain Deck.

Recommended cards
Monsters

Iron Chain Blaster
Iron Chain Coil
Iron Chain Repairman
Iron Chain Snake
Lava Golem
Needle Worm
Salvage Warrior (allows "Iron Chain Coil" to be brought back for a Level 8 Synchro Summon)
Marauding Captain (use its effect to bring out "Iron Chain Coil" and Summon "Iron Chain Dragon" in one turn)

Spells

Gravekeeper's Servant (Control)
Card Destruction
Hand Destruction
Paralyzing Chain
Shrink (For winning battles and triggering the Iron Chains' mill effects)
Poison Chain
Dark Room of Nightmare (Can be used with "Paralyzing Chain" to inflict a further 300 points of damage)
Book of Eclipse (can flip all monsters on the field face-down, allowing the reuse of "Needle Worm")

Traps

Threatening Roar
Strike Slash (Piercing)
Waboku
Skull Invitation
Fatal Abacus
Cemetary Bomb
Scrap-Iron Scarecrow
Magical Thorn
Gravity Bind
Meteor Flare (Helpful if the Duel is nearly finished with the opponent's LP at 3000 or more)
Chain Destruction (Helpful in weeding out opponent's Deck)

Synchros

Iron Chain Dragon
Magical Android (For healing if need be)
Blood Mefist
Stardust Dragon
Black Rose Dragon

Xyz

Wind-Up Zenmeister (Can flip "Needle Worm" back down, forcing the opponent to discard 5 more cards at the End Phase)

Dark Diviner's Return

This Deck is based off using "Dark Diviner" alongside Iron Chains in an attempt to maximize the amount of cards being milled from the opponent's Deck. The cards listed below are cards that can be used in such a Deck. Below are some tips for this strategy:

Use "Junk Synchron" along with "Dark Bug" in this Deck, as both cards can be used to revive the other from your grave-yard for an immediate tuning.
While "Junk Synchron" can't be played face-up on the field in the same turn "Worm Bait" was used, it can be played face-down on the field OR Summoned next turn to use with one of the remaining "Worm Tokens" to Synchro Summon "Dark Diviner".
"Regretful Rebirth" can be used to Special Summon either a "Shield Worm" or "Warm Worm" that was destroyed by battle this turn to mill more of your opponents cards.
"Worm Bait" can also boost the number of cards sent from the top of the opponent's Deck when combined with the effect of "Shield Worm".
"Call of the Haunted" is great for bringing back "Warm Worm" or "Shield Worm" for more card drainage, as well as reviving a "Dark Diviner" that was destroyed by an opponent's card effect.
Equip an opponents monster with "Iron Chain Snake", and then have "Dark Diviner" attack the same monster. Your opponent will have to send at least 3 cards - plus any number of cards equal to that monster's Level - from the top of their Deck to the Graveyard.

Monsters
Spells

Monster Reborn (Brings back "Shield Worm", "Warm Worm" and "Dark Diviner")
Worm Bait

Traps

Call of the Haunted
Regretful Rebirth

Extra Deck

Ancient Fairy Dragon
Dark Diviner
Wind-Up Zenmeister (can be used to flip a "Needle Worm" face-down (preferably after it was flipped face-up that turn) and force the opponent send another 5 cards from the top of their Deck to the Graveyard at the End Phase)