Creative Deck Strategy: True Slime Monsters

You’ve heard of Kaiju Graydle, but come check out what happens when you throw Wyrms into the mix!


Welcome to another article, and this time we are shifting back to the watery depths, cause out from the puddles rise the slime animals more commonly known as the Graydle archetype. It is an archetype of WATER Aqua-type monsters based on the Roswell Grey Aliens that revolves around stealing your opponent’s monsters from right under their nose. Talk about nailing the execution of a theme from its background. They also have a bit of a Synchro element to the archetype, as they feature the first (and only) Aqua-type Synchro Monster! It just happens to be named Graydle Dragon, cause logic. Anyways, it quickly became a trend to splash in one of the recent TCG World Premiere archetypes, the Kaiju, in order to artificially give your deck boss monsters to steal. Since at the end of the day, you really were just giving them a boss for you to steal back moments later. This was definitely a great path to making the Kaiju archetype function effectively, but in all honesty, the Graydle monsters really only serve as a sidebar supporting our Godzilla overlords. But that all ends today, because we finally have a way to make the Graydle shine even brighter, while still fitting in those important Kaiju to eliminate threats that cannot be targeted. Everybody, let’s say hello to the theme based around the REAL Kaiju Monsters!

BahrstosFuhrertheTrueDracoruler-INOV-JP-SRI’ll start by introducing the soon to be first member of the theme in TCG land, True King Ashnimazud, the VanisherEven though it hasn’t quite hit the TCG landscape, I don’t actually expect it to cause any large metagame shifts. Sure, it triggers the Fire King monsters, but it really only works effectively if you have other Wyrm-type monsters to abuse its second effect. And in which case, you’re just better off running a pure Wyrm-centric deck. But when you do have another Wyrm, such as another True King perhaps, it becomes all that much more potent. The monster pictured at right, which the Org has translated into Bahrstos Fuhrer, the True Dracorulerserves as the other half of our neat True Kaiju engine. For each of them, you need to destroy 2 monsters among those on your field or in your hand, one of which must be its attribute, and then it is Special Summoned. If you happen to destroy 2 monsters with the same attribute, that means that you get an additional bonus effect! For the FIRE True King, that is a banished monster between the field or Graveyard. Similarly, for the WATER True King, that is 2 Spells or Traps banished from the field or Graveyard. But we’re more focused on the possibility of synergy here, so let’s focus on what it can do for Graydles. Well for one thing, either triggers your Graydle Eagle while summoning itself, and that is always a great way to steal an opponent’s monster. But the best part of this synergy is that Graydle Split actually has 2 additional amazing targets to destroy in order to summon 2 Graydle straight from your deck, since each of the True Kings has an additional effect that only activates when it is destroyed by a card effect. Such a nice coincidence there.

On top of all of these neat bits of synergy between the three archetypes/themes, the Graydle are going to be getting even more support in an upcoming booster set, Invasion: Vengeance. Remember folks, when new cards come around, legacy themes can sometimes benefit even more than you’d expect. Just take a look at the legacy support for Graydle – the most important of which is Graydle Slime Jr. It appears to be the amorphous child of Graydle Slime, as it shares the tuner status and similar body features. This new monster even gives you Special Summoning power from the Graveyard in order for you to bring back the non-tuner materials that you require, just like daddy. The best part is, you can even bring back another copy of itself, and Xyz Summon into TreatoadYup, this little guy can find a use outside of Frogs since it is a powerful omni-negator for all WATER decks, but it works particularly well in Graydle due to the entire archetype being Aqua-type. This gives the deck even more power, but in particular, it gives the archetype a ton of disruption potential, because it now has the ability to defend its own power plays. So let’s recap – this strategy gives your opponent boss monsters, steals them back, Synchro Summons into field-clearing Dragons, Special Summons Wyrm after Wyrm, banishes your opponent’s monsters or Spells and Traps without targeting, and Xyz Summons into an omni-negator. Oh, and did I mention Graydle Impact which lets you destroy or search every single turn? The key takeaway is that this deck truly does have quite a wide range of options, and it is definitely a force to be reckoned with for an unprepared opponent.

Now I’ve briefly brought up a ton of the individual cards, dipping a tiny bit into the strategy, but you’ll notice that I don’t have as much indepth descriptions as my past articles. Simply look at the card design for your answer – Graydle is a very straightforward archetype: they die, you steal your opponent’s monsters, you win. Thus, I’d much rather spend more time in this article talking about card advantage and game sense that applies to this deck, but also in general. You see, many of the monsters we are running are summoned at hefty costs, especially with a build like this. Cards such as Graydle Slime or True King Ashnimazud, the Vanisher require heavy investments: you need to destroy two cards just to be able to Special Summon any of them. So how do you decide the correct time to strike and move forward with your gameplan?First off, you need to ensure that your plays will not be for nothing. If you do decide to activate any of these high-risk monsters, you need to be sure that your effect will resolve properly and in its entirety. You do not want to destroy 2 Graydle, only to have your Water True King’s summon be fruitless due to a rouge Bottomless Trap Hole. BUT, you must be aware of your own abilities and weaknesses as this True King Graydle Kaiju strategy is a particularly passive deck. You sometimes must rely upon your opponent to summon out strong monsters for you to then steal to get back into the duel. Just remember, you need to be walking the fine line between luring your opponent in and making strong plays of your own. Never forget: you can also turn to your own Extra Deck as well to summon out boss monsters. As an example, Phantom Fortress Enterblathnir serves brilliantly with your True King monsters, since they all happen to be Level 9. If you happen to summon out the WATER True King by destroying another copy, you already have your two Level 9s for your Xyz Summon! And never forget using Graydle Split to get out materials for an Xyz or Synchro Summon.

So in conclusion, with this strategy you have options, but you need to play smart. I cannot drill this idea into your head enough. On paper, Graydle may seem like a beginner’s deck, since you really have simple effects. But in terms of actual strategy, sometimes the monsters with the most simple effects can be used in the most elaborate combos. To use this deck properly, you have to know how to bide your time, analyse the threat your opponent poses at any given point, and then choose your plays wisely. This advice can even be taken to heart for whichever deck you choose to build in the future. But enough about generic deckbuilding and play, let’s cover the key cards and additional techs for this slimey mashup!

Key Cards:

  • Graydle Eagle, Graydle Alligator, Graydle Cobra
    • These are your main monster-snatching archetype members. You will win or lose depending on whether or not you successfully snatch something away, even if it is a Kaiju that you hand-delivered to them.
  • Graydle Slime, Graydle Slime Jr.
    • These are your tuners. Each provides a key way to Special Summon non-tuners, and each provides a different path to get into Graydle Dragon. He is very important.
  • True King Ashnimazud, the Vanisher, Bahrstos Fuhrer, the True Dracoruler
    • These Monsters (cough cough True Kaiju) are your secret weapons, ready to be spring upon unsuspecting opponents. Other than these new threats, you are using a generally passive archetype in Graydle. They will certainly be surprised when you throw up these monsters and switch into an aggressive beast of a deck. Also, these serve as an additional out to specific floodgates or untargetable threats.
  • Gamaciel, the Sea Turtle Kaiju, Dogoran, the Mad Flame Kaiju
    • These should be the two Kaiju monsters that you run in your deck. Not only because they are both pretty good things to Special Summon with Slumber, but they also are WATER and FIRE, the perfect attributes to trigger the banishing effects of your two True Kaiju.
  • Graydle Impact, Graydle Split
    • These are your two main archetype support cards that give you the search power you need and the Special Summoning power you dream about. Between the two of them, your deck will be fast enough to compete with the best of them.
  • Interrupted Kaiju Slumber
    • Hailed as one of the most powerful Kaiju support cards ever created, this Spell rids the field of monsters before summoning out 2 Kaiju. If you happen to destroy your own Alligator with its effect, your opponent’s Kaiju disappears too!

Additional Tech Options:

Most of these additional tech options work well to augment the strengths of your deck. Some are a bit more far-fetched than normal, but not all of them.

  • Graydle Parasite – Another support card for our Aqua theme of the article. This one lets you bring back monsters from your opponent’s Graveyard to steal, or it lets you Special Summon your Graydle straight from the deck if your opponent is trying to sneak through a direct attack. It is a versatile tech option that definitely can put in work.
  • Graydle Combat – The second new support card in the upcoming Invasion: Vengeance set. This one lets you negate targeting card effects from trying to avoid triggering your Graydle monsters. And if it isn’t the correct effect type, then you can just negate the effect all together. Powerful, yet situational, so I leave this up to personal preference.
  • Tailor of the Fickle – What an old card!? This Quickplay spell lets you change one of your equipped Graydles to take control of a new monster. It definitely is a tech option that your opponent won’t expect, while still being a pretty cool option.
  • Surface – Need a themed Monster Reborn? Look no further. This card is also particularly useful, alongside Salvage, because you want to have more fodder to destroy away to summon out your True Kings.
  • Neo-Spacian Grand Mole – If you ever want to just keep bouncing your Kaiju monsters, this is a potential option for you to consider!
  • Pot of Duality – Some decks just need to get to key cards faster. In combo-heavy decks like this, Duality is always a good option, especially when you do have the option to sit back behind a Graydle Parasite, or really any of your Graydle monsters. 
  • Lose 1 Turn – If you’d like to keep pressure on the opponent, run this Trap card to limit their monster options even further. 
  • Moon Mirror Shield – If you can’t take them, just run over them. This is one deck where you will always have monsters at your disposal, and it does solve the problem of unaffected or un-targetable boss monsters. Both of these are fairly prevelent in today’s Yu-Gi-Oh world after all.
  • Ice Hand & Fire Hand – The WATER and FIRE monsters that you can use as Summoning fodder for your True Kings. Plus, they both have additional destruction capabilities.
  • Super Quantum Red Layer Super Quantum Blue Layer – Another WATER/FIRE engine to consider to augment your deck further. As with other recent articles, run this engine alongside Emergency Teleport if you do choose to try to fit them in.
  • Supply Unit – When running a deck that enjoys destroying its own monsters, you may want to consider this as a functional and effective draw engine. Especially if you wish to compensate for all of your destruction effects. 

Check out the spoiler below for a sample decklist:

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As always, the above list is just my personal build. The Graydle archetype may be finnicky, but it is always something that can be really fun to play if you play against opponents that tend to leave strong monsters out on the field! Until the next time, keep innovating and building creative decks! Most of all, just enjoy dueling for the fun that it can be!

Reminder, I also take suggestions for future CDS articles! While I will not run out of cool ideas, I do want to be writing articles about strategies you are interested in. So if you desperately wish to see a CDS article about the archetype, theme, or strategy you love, feel free to private message me on the YGOrg Discord server or the YGOrganization Forums with your ideas to keep under consideration: my username is Quincymccoy.


Hello everybody! I serve as Number VIII of the Organization; however, my main role on the site is writing regular Deck Strategy articles! I enjoy fleshing out archetypes to their fullest potential and helping people discover amazing new techs and decks to try out!

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