"Entity" is a series of Extra Deck monsters, initially introduced as Korean-exclusives in Legacy of the Valiant. It is based on combining the use of Fusion, Synchro, and Xyz Monsters, specifically its three sub-archetypes: respectively, they are "Elder Entity", "Old Entity", and "Outer Entity".
This series is based on cosmic entities in H. P. Lovecraft's Cthulhu Mythos. The "Elder Entities" are based on the Elder Gods, the "Old Entities" are based on Great Old Ones, and the "Outer Entities" are based on the Outer Gods.
|Elder Entity N'tss|
|Elder Entity Norden||Nodens|
|Old Entity Cthugua||Cthugha|
|Old Entity Hastorr||Hastur|
|Outer Entity Azathot||Azathoth|
|Outer Entity Nyarla||Nyarlathotep|
|Forbidden Trapezohedron||Shining Trapezohedron|
The Deck is based around the synergy between the archetype's Fusion, Synchro and Xyz Monsters. The main purpose of the deck is to overlay a Fusion Monster and a Synchro Monster to Xyz Summon "Outer Entity Nyarla", who is then used to Summon "Outer Entity Azathot", who can use its effect to destroy all cards the opponent controls if it has all three of the aforementioned monster types as its Xyz Materials. "Entities" have no Main Deck monsters and only a small number of Spell/Trap support, which forces them to play either generic cards or adopt a second archetype to work with.
The simplest way to Summon "Azathoth" used to be "Instant Fusion" to Summon "Elder Entity Norden"; "Norden" basically allowed the deck to Special Summon the necessary materials for the Xyz climb by reviving "Old Entity Cthugua" or "Old Entity Hastorr", then overlay them into "Nyarla" and then "Azathoth", which then resulted in the aforementioned board wipe and opens the opportunity for an OTK. However, the idea of using "Norden" in combination with "Instant Fusion" spread like a wildfire and was soon used and abused in all sorts of decks, using "Norden" as easy access to all manner of things. This soon caused his ban in both the OCG as well as the TCG, and simultaneously hit the Entity archetype hard.
The introduction of Link Monsters in Yugioh, however, hit "Entity" even harder than many other decks. Before Master Rule 4, the only problem the Entity player had to face in building a board was getting enough monsters to do the necessary summons. With Master Rule 4, the Entity player cannot just start playing the archetypes Extra Deck monsters, but instead needs to push out a Link Monster with at least two Link arrows unlocking your own Main Monster Zones. A Special Summon of "Azathoth" in one turn therefore needs an insane amount of cards and tends to make matters rather inconsistent. "Norden" actually was paramount for the overall consistency of this Deck, but even without his insane effect, he would be better suited for the "Entity" deck than his counterpart "Elder Entity N'tss". "N'tss" not only suffers from having a way worse effect than "Norden", she is also extremely impractical due to her inability to be summoned in any other way than Contact Fusion; this forbids any reviving, and therefore recycling, of "N'tss" and also disallows her to be summoned by the otherwise incredibly useful "Instant Fusion". To go into "Nyarla" and afterwards into "Azathoth", a level 4 Fusion Monster is required and "N'tss" is a horrible choice for the deck. Unfortunately, to add insult to injury, only a few other Level 4 Fusion Monsters exist and most of them are also very lackluster.
Since the deck also needs to be able to Synchro Summon its two "Old Entity" monsters "Old Entity Cthugua" and "Old Entity Hastorr", one has to be aware of the levels of the Main Deck monsters. "Cthugua" is capable of softening the huge minus that results from the summoning chain leading to "Azathoth", while "Hastorr" helps out in a rather unique way by potentially stalling and stealing the opponent's monsters.
The Spell and Trap line-up of "Entity" consists of three cards: "Dreamland", "Forbidden Trapezohedron" and "Forbidden Apocrypha". Sadly, all of these cards became almost completely irrelevant due to the advent of Link Monsters, since all of them need a sizeable amount of non-Link monsters on the field to work; and the pay-off for even building a board that allows these cards to function is not worth mentioning. “Dreamland”, while already being pretty mediocre before, is even worse with Link Monsters in existence since its effects are void in most situations. The same is true for “Forbidden Apocrytha” due to most players not really building huge boards consisting of mostly Fusion, Synchro or Xyz monsters. The biggest victim of Master Rule 4, however, is “Forbidden Trapezohedron”: Before the introduction of Link monsters, this card was a play-enabler to get whatever piece for “Azathot” was still missing; nowadays, you would need a Link-3 conveniently unlocking zones with all its arrows AND two of either Fusion, Synchro or Xyz monsters. You can still revive the necessary monsters from your graveyard to get them on the field without the need for Link monsters, but all of this work for a monster that just disappears as Xyz material is ridiculous, making “Forbidden Trapezohedron” nigh unplayable.
As mentioned before, "Entity" needs to borrow another deck idea for the Main Deck to function. One potential Deck to use is a Warrior Deck. "Marauding Captain" and "Junk Synchron" allow for the quick summoning of monsters to set up for the summoning of Level 4 Synchro Monsters and Rank 4 Xyz Monsters. The Deck's access to "Reinforcements of the Army" and "The Warrior Returning Alive" also increases flexibility depending on what type of monster the player needs. "Doppelwarrior" and "Tuningware" are also useful in getting Level 1 and/or Level 2 monsters into play for Synchro Summons.
Another candidate for the deck building could be "Cyberse". "Cyberse" monsters are capable of swarming via either using multiple Normal Summons or by Special Summoning from almost all available zones in play and also support the overall idea of Xyz, Fusion and Synchro Summoning. Balancer Lord can allow a second Normal Summon, which is helpful in combination with cards like Widget Kid, Cyberse Gadget or Clock Wyvern. The Deck also could get more consistency in form of Cynet Mining, Lady Debug and Flame Bufferlo, all either fetching useful cards or simply building towards a more adventageous board state.
Cards like "Xyz Override" and "Xyz Unit" can be used to allow "Azathoth" to use its effect multiple times; although it should not be necessary to erase the board more than once. "Synchro Fusionist" also was an excellent support card for this deck, mostly allowing the searching of "Instant Fusion" and "Re-Fusion" for "Norden", but depending on the deck can certainly still be helpful.
- The Deck's major problem is consistency—the unusual combination of cards needed to support so many different summoning methods means the player may have a hand full of cards that do not work together to accomplish the Deck's objective. The reliance on quickly performing these Summons also makes the Deck bad for hand advantage, and their momentum can be halted if the opponent is able to stop their combo in progress.
- The size of the Extra Deck is also a problem—the player is unlikely to have much room for monsters outside the "Entity" theme, and thus their deck may lack versatility.
- "Maxx "C"" can be used against an "Entity" Deck, since it needs to Special Summon a respectable amount of monsters to reach "Azathoth".
- Any form of summon negation can be devastating, making cards like "Solemn Judgment", "Solemn Warning" or the "Ghost Girl" Handtraps effective counters against the overall "Entity" strategy.
- The end goal for the "Entity" strategy is to use "Azathoth's" nuke effect; therefore, any effect negation that isn't a monster effect will halt the entire deck.
- Any cards that bounce their target are even more effective since most monsters the "Entity" player has on board will be from the Extra Deck and therefore return there with a huge loss in resources for the "Entity" player.