Forum:Reasons why cards are Forbidden/Limited in Duel Links

List of Reasons for Why Cards are Forbidden/Limited in Yu-Gi-Oh! Duel Links
Card Name	Reasons
Forbidden
None yet.	None yet.
Limited 1
Cyber Petit Angel	Cyber Angels proved to be highly resilient even after the Limitation of two of the deck's key cards, with a variant that made use of Saffira, Queen of Dragons (whose Ritual Spell provides similar protection to MAR) proving popular. A searcher for whatever combo piece the CA player needed. The resulting combo was too powerful for its time. Later moved up the list, which is a boost to CA as it lets them run it alongside Dakini and MAR.
Dyna, Hero Fur Hire	Big power card of the Fur Hire deck. Searchable by Beat, Bladesman Fur Hire, and easily Special Summoned from the hand by a good number of low-level Fur Hire monsters. Nullifies Graveyard setup on Summon. Must be at 1 because if 2 of them are out (a definite possibility in the Fur Hire deck), one can prevent their opponent from attacking at all, à la Marauding Captain.
Gem-Knight Lady Lapis Lazuli	Used as part of a powerful burn FTK, just as in the TCG. This was initially unwieldy, but became more and more viable with 3 copies of it available and Master Diamond to copy it, and access to Block Dragon to give the FTK more consistency seems to have been the final straw.
Koa'ki Meiru Maximus	Boss monster of Koa'ki Meiru. Can be Summoned simply by banishing 1 Iron Core. Searchable by Diamond Core... which can then be banished from the Graveyard to prevent the self-destruction effect from going off. Can costlessly remove anything. The crux of Koa'ki Meiru's use as a ludicrously fast OTK deck.
Vision HERO Vyon	Highly versatile in HERO decks, especially Destiny HERO. Sends a HERO monster straight from the Deck to the Graveyard, which synergises well with Destiny HERO - Celestial (Semi-Limited). Can also be used to search Polymerization, which more often than not is a quick way to Destiny HERO - Dangerous given you likely will have another Destiny HERO in your hand. Is also a DARK Mask Change target, which allows an OTK with Masked HERO Anki.
Woodland Sprite	Combined with the Bamboo Sword engine, this card easily caused FTKs as the player could rapidly draw through a whole Deck of Equip Cards. It was quickly Limited after it was released, with Konami announcing they would look into the engine that enabled it as well - which they eventually did.
Golden Bamboo Sword	Combined with Broken Bamboo Sword and Cursed Bamboo Sword coming from the same pack, it made up a powerful draw engine allowing the player to draw through their Deck in a single turn. This enabled FTK strategies involving cards such as Woodland Sprite (also Limited) and Magical Citadel of Endymion. Was Limited in a second emergency banlist in a row.
Restructer Revolution	800 damage first turn isn't bad in an 8000 LP format, but with 4000 LP it's devastating. "Téa Burn" decks comboed this with Cup of Ace (which would either stuff your hand or help them draw into their stronger cards) and Téa's skill "Duel, standby!" which added a card to each player's hand. Combined with other burn cards, this led to FTKs and made up the first truly hated deck archetype in Duel Links. Was the first card to be Limited.
Spellbook of Eternity	Key part of any Spellbook deck. Allows the user to recur a banished Spellbook of Fate (Semi-Limited), or Spellbook of Secrets or any other Spellbook card that was banished to activate Fate's non-targeting banish. Limited to help diversify the meta.
Amazoness Onslaught	Key card in Amazoness decks. Searched easily by Amazoness Princess and, when combined with Amazoness Queen, can turn Amazoness into indestructible monsters that banish whatever they battle (and damage you for the trouble, in the case of Amazoness Swords Woman). Overall highly oppressive to the meta, which required other decks to use valuable space on pure backrow removal, such as Cosmic Cyclone, to stand a chance. Decks were defined by how well they could play around Onslaught, rather than their own merits.
Champion's Vigilance	There are far too many ways to bring high-level Normal Monsters out. Once you've got your high-level monster and copies of CV out, you can stop your opponent from doing pretty much anything. Limited at a time when Red-Eyes decks were topping easily.
Massivemorph	Powerful card in burn and stall decks. Regularly used in decks with minimal presence for monsters on the field, as it made a monster completely unable to attack in that situation, as well as a bigger target for Amazoness Swords Woman. Could even be copied by the Skill Extra, Extra for additional pain, before the nerf of that Skill.
The Sanctified Darklord	A key card in Darklord format. Negates a monster's effect and gains large amounts of LP. Can be copied by most Darklord monsters to be used multiple times in one turn. Turns a Duel into beatstick vs. beatstick (which Darklord usually win), and causes massive LP gain.
Limited 2
Amazoness Princess	Offers an easy way to search Amazoness Onslaught (Limited), and pulls Queen directly from the Deck. Simply having this card in your opening hand provides serious advantage.
Amazoness Swords Woman	Used endlessly in stall and burn decks, as an opponent destroying it will take damage. Made up part of a near-universal stalling engine involving Princess and Onslaught.
Cyber Angel Dakini	At 3, this was far too powerful for the Duel Links meta. Easily searched, and easily summoned in its own deck (with the help of cards such as Cyber Petit Angel, the other Cyber Angels, Senju of the Thousand Hands, etc.). Non-destruction removal when it's summoned. Recycles Machine Angel Ritual (also at 2) at the end of the turn, effectively making the Limitation of MAR pointless. Even with MAR Limited, Cyber Angels ran riot over the November 2017 KC Cup, to the point where the 7 most used card spots were taken up by the deck's key cards.
Donpa, Marksman Fur Hire	Key part of the Fur Hire deck, searchable by Beat and easily summoned by all the others. Gives easy destruction of an opponent face up card (usually a monster) when it's Summoned.
Hiro's Shadow Scout	Preemptively hit around the same time as the Sylvan, Masked D-HERO and Silent Swordsman hits to eliminate the threat of a certain Deck type becoming too prominent. Which Deck that is remains to be seen.
Legendary Six Samurai - Enishi	Offers non-destruction removal that is easily accessed in the Six Samurai deck. Easily found through Shien's Dojo or the destruction effect of Secret Six Samurai - Fuma, meaning preventing your opponent from Synchro Summoning Legendary Six Samurai - Shi En wouldn't stop the opponent from OTKing or shutting you down. Hit after consecutive formats of unchallenged Six Samurai dominance.
Rose Lover	Very powerful utility card in Plant decks. Most notably used in Sylvans, where it was easily sent to the Graveyard by all of the archetype's cards, as well as World Carrotweight Champion, and then used to summon a larger Sylvan and set up OTK boards.
Wiz, Sage Fur Hire	Strong card in Fur Hires. Searchable with Beat and Summonable quickly after that. Can negate a card every turn, which can either disrupt an opponent's play or nullify defensive backrow, making it very difficult to avoid being OTK'd.
Assault Armor	A card that gave consistency to the Silent Sword Slash OTK. Limited to stop it from becoming overpowering.
Cup of Ace	50/50 chance to draw 2 cards. Often used in stall and burn decks, but later became busted with the skill Master of Destiny, which turns it into a Pot of Greed.
Darklord Contact	A revival card that can be copied to be used multiple times per turn... which produces more Darklords to copy more copies of this card (or give fuel for The Sanctified Darklord).
Diamond Core of Koa'ki Meiru	Searches any Koa'ki Meiru card, including the Limited Maximus. No once per turn restriction. Was used to easily protect a full field of Koa'ki Meiru monsters from destruction, making a beatdown strategy involving them viable.
Enemy Controller	Highly versatile competitive staple that fits right into most deck types. First effect can slow down the Duel, while second effect can end a Duel quickly by leaving the foe open for direct attacks.
Hey, Trunade!	Non-destructive backrow removal. About as powerful in Duel Links as Giant Trunade was in the TCG. Only contributed more to Amazoness dominance, as Onslaught could simply be flipped face-up and not be affected by this card.
Machine Angel Ritual	Cyber Angel cards were first added in the GX update, and to say that they were overpowered is an understatement, as the deck shot immediately to Tier 0 status. Makes Cyber Angels much harder to destroy. Initially Limited, but now CA decks effectively have to choose between 1 MAR + 1 Dakini or 2 of one of them. This helps to limit the deck's devastating power.
Neos Fusion	A one-card engine. Lets the player dump whatever Effect Monster they want in the Graveyard to Special Summon Elemental HERO Brave Neos, then another copy is searched by that Brave Neos. Popular generic options for the Effect Monster included Bacon Saver for attack negation, or A/D Changer to weaken beaters with low DEF. Powered up all kinds of Decks, until its interaction with Invoked was likely judged to be the final straw.
Secret Pass to the Treasures	Key card in the Silent Sword Slash OTK, along with Assault Armor (above). Its only other real use is in farming decks, of which the vast majority don't run more than 1.
Shien's Dojo	Key card in Six Samurais. Getting this out and then Normal Summoning a Level 4 Six Samurai gives immediate access to Secret Six Samurai - Fuma, which leads to Legendary Six Samurai - Shi En and its powers of negation. No once-per-turn restriction means running multiples could lead to multiple copies of Shi En in a single turn.
Silent Sword Slash	Extreme boost in power and protection for any Silent Swordsman, and searches on top of that. Was previously used to OTK. Hit in anticipation of the release of a Structure Deck focusing on Silent Swordsman, which would have become far too powerful with this at 3.
Spellbook of Fate	Important versatile card in Spellbook decks. Searchable by most of the other cards in the deck. Offers non-targeting removal of most threats during either player's turn. Banishing Spellbooks from your Graveyard also allows them to be revived through Spellbook of Eternity.
World Legacy Clash	Generic Quick-Play Spell with a variety of benefits. Temporarily removes your monster, but permanently cripples the opponent's. Can also be used to avoid your opponent's cards that would destroy or weaken your monster. Most potent in Decks that can make high ATK monsters easily, such as Six Samurai, Darklords, and most Neos variants.
Pulse Mines	Better than Windstorm of Etaqua in Machine decks, because it stops the opponent from attacking at all for a whole turn, enabling setup of complex strategies. Hit due to heavy use in Geargias.
Treacherous Trap Hole	Powerful removal that can shut down an opponent's play. Not even playing only one monster will keep you safe, as it can remove the user's monster as well. The downside (requiring no Trap Cards in the Graveyard) is immaterial to several decks that don't use many Traps anyway, such as HEROes and Spellbooks.
No longer on list
Amazoness Baby Tiger	Aids the Amazoness in swarming by Special Summoning itself from the Graveyard, and adds a free tribute for Amazoness Queen if necessary. Evidently, the ability to run 3 of these along with 2 Onslaught was too powerful. Brought back after Onslaught's Limiting ended the dominance of that deck.
Destiny HERO - Celestial	Key combo maker in Masked D-HERO decks. Synergises very well with Vision HERO Vyon (at 1). Also acts as removal and burn in some situations. Came off the list as D-HERO based decks are no longer considered much of a threat.
Samurai Skull	Has been a staple in any Deck that uses Zombies, for a long time. Dumps whatever Zombie you want in the Graveyard. Was initially seen as a budget alternative to Gozuki in Red-Eyes Zombie decks, but really came into its own in Vampires, where it was usually used to dump Vampire Retainer, which then searched Vampire Kingdom when Special Summoned. Was hit to help diversify the meta, and once that was achieved, came back.
Sylvan Marshalleaf	Key card in Sylvans. Easy monster removal when placed in the Graveyard by the other Sylvan cards, causing OTKs in some cases and powerful boards in most others. Placed on the list to promote deck diversity, as Sylvans were proving overwhelmingly popular in PvP. Nowadays, though, they're much too slow to function, especially with Rose Lover still at 2.
Iron Core of Koa'ki Meiru	The card that Koa'kis need to function. Searchable by Diamond Core. Can re-add itself to the hand every single turn. Part of the Summoning condition of Maximus (Limited). Freed as Diamond Core was hit.
Red-Eyes Spirit	Red-Eyes' revival card and key enabler of the Red-Eyes boom that turned most Duel Links duels into dittos. Combos well with Red-Eyes Insight and/or Cards of the Red Stone. Can revive Red-Eyes monsters during the Battle Phase so they can attack again, leading to some nasty OTKs. Dropped off the list because the deck isn't anywhere near as good in the current meta, especially with Champion's Vigilance still at 1.

This was created so that people didn't need to wonder why cards were limited in Duel Links. Yes, the table is taken from the OCG/TCG reasons page. No, it really doesn't matter.

Remember, Duel Links handles the F+L list very differently:

• You can only have 1 Limited card overall in your deck.
• You can only have 2 Semi-Limited cards overall in your deck.