Yu-Gi-Oh! Deck Debut: Gem-Knight 2025

The history of Gem-Knight is a storied one, debuting in Hidden Arsenal 5 back in 2011, well over a decade ago, as an ode to HERO with its Normal Monsters and elemental theming.  It took quite some time for the deck to be good, however, and throughout the course of Yugioh’s history, Gem-Knight has never been good without doing something sincerely degenerate.  Notably, this often involved Block Dragon, a card banned in the TCG, but Limited in the OCG, but in either case hinged on killing the opponent before they even got a chance to play.  For that reason, Konami’s been hesitant to print good Gem-Knight cards, and the ones they have printed bear numerous reminders not to deal effect damage; while that last part hasn’t changed, the truth is that the new Gem-Knight cards releasing in Battles of Legend: Monster Mayhem are exceptional.  Not only have they seen several tops in the OCG, but they might even be better stateside without the threat of Maxx “c”.  Let’s do a quick dive on those brand-new cards, and take a look at Gem-Knights in 2025.

Long gone are the days of looping your Normal Monsters with Gem-Knight Obsidian: Now, Gem-Knights are all about their effect monsters, and thankfully have good reason to be.  Gem-Knight Hollowcore is a spin on Mathmech Circular for the archetype, being able to set up Gem-Knight Fusion to in the GY to Summon itself, and then serving as an omni-negate while in the graveyard.  Alarmingly, while a free extender that’s also an omni is good, the fact you put GK Fusion in the GY means it’s immediately accessible if you can banish 2 additional names, which you’ll certainly have access to.  The second of these new cards is Gem-Knight Nepyrim, a pretty standard Stratos-style searcher that gives you an extra Normal (especially useful for your non-once-per-turn Gem Armadillo) and can bounce back when binned.  Finally, outside of the Extra Deck, you have Gem-Knight Dispersion…a frankly absurd card I cannot believe saw print.

Dispersion is at face value a reasonable Fusion Spell or searcher, but where it truly gets out of hand is the clause in its first effect, “you can also use up to 2 non-Rock "Gem-Knight" monsters from your Deck or Extra Deck”.  This allows us to in turn bin Nepyrim and/or Gem-Knight Quartz, which both resummon themselves and add a card back, respectively.  The card you’re most often Summoning with Dispersion, though, is aptly Gem-Knight Master Diamond Dispersion.  He ports out into 3 different names, and then recurs himself, loading up the yard for Hollowcore and dodging targeted negation extremely well.  This card alone is backbreaking against Mitsurugi, as their own effects allow you to continue your value loop on both player’s turn. 

Another component of the deck is in its Roses, Crystal Rose and Brilliant Rose.  While Brilliant is a Gem-Knight, Crystal Rose is not, meaning normally it would be quite difficult to search.  Fear now, however, because you’re able to readily employ Spright Sprind as part of your mainline combo, and Crystal Rose can Summon itself from the GY to bin another name.  This promotes a feedback loop of sorts, where any hand that can access Spring can access all 3 of your core Gem-Knight names, which float or are Summoned by effects when moved between the hand, field, and GY.  For this reason, you’re left with a strategy that is exceptionally resilient to hand traps and interaction, as the number of malleable 1-card combos, or so-called 1.5 card combos which require some generic discard, are plentiful.

But in this list, as has been popularized in the OCG, we’re on a secondary package.  After all, in order to best make use of Nepyrim, we need to send it from the hand or deck to the GY, such as by way of Fiendsmith Tract.  Yes, against all odds, the omnipotent ‘everything engine’ of Fiendsmith has infected the Gem-Knights, but goodness it feels good.  This list is playing a comprehensive Fiendsmith package, with double Fiendsmith Engraver, Lurrie+Tract, and Fiendsmith in Paradise for our opponent’s turn.  Of course Tract has value in adding a non-Lurrie name and discarding Nepyrim, but we can always discard Lurrie for similar value, as both of our engines do their best to be competent 1-cards through negation.  If Gem-Knight baits out the Ash Blossom, Fiendsmith swoops in, and vice versa.  The crucial factor, here, is that Gem-Knight is shockingly good against exactly Droll & Lock Bird, which is seeing Main Deck play at the moment.

Against Droll, while you do miss out on searches with your Gem-Armadillo, you still get to send with Hollowcore and recur with Nepyrim—all Droll does is turn off your repeatability.  In a similar vein to Ryzeal, Droll isn’t actively hurting your core setup, it’s hurting you the turn after, if an opponent manages to break through your common endboard of Fiendsmith’s Desirae and Gem-Knight Master Diamond Dispersion.

Although they have been limited, both Triple Tactics Talent and Crossout Designator do provide a means of insulating against this format’s menaces from the hand, but really you’re not looking forward to it, even still.  Dominus Impulse on your first Fusion Summon can be backbreaking, doubly so if it comes from the effect of Gem-Knight Phantom Quartz, your Link Vrains Pack Link Monster that was pushed even back when it was released.

In terms of non-engine, this deck is able to slot in a respectable 16, with a huge amount of slots for improving its going-first gameplan, given we’re on 7 copies of the Mulcharmies, in the standard 3:2:2 split that’s been popularized since the release of ALIN.  This can come in the form of Artifact Lancea and Chaos Hunter for Maliss, or even The Winged Dragon of Ra - Sphere Mode and co, given we have extra Normal Summons available by way of Nepyrim (can you tell how many problems that card alone fixes?).

You would think going second would be problematic for this deck, but given Lancea doesn’t really do all that much, as we’re often banishing Hollowcore on the opponent’s turn and don’t necessarily need Crystal Rose if it’s trading for a Lancea proc, it’s not a massive ordeal.  A huge amount of Mulcharmies in the main helps out, and we can always slot in board breakers over cards like Foolish Burial, here designed to help kickstart our plays by way of Engraver or Nepyrim.

This list has been adapted from an OCG list that managed a 1st place finish in a 122 person tournament, which isn’t shabby at all!  It has all the hallmarks of a midrange deck, from a tight Extra Deck to numerous meta calls in the form of a second Engraver.  The one thing this deck loses out on, though, compared to its purer peers, is a wider suite of Gem-Knight Fusion Monsters.  We’re on a scant 5 names, meaning it’s very possible we run through the entire lineup in a single turn, and need to find a shuffle effect to keep going.  If we had extra room, you could slot in Gem-Knight Lady Brilliant Diamond or even some tools like Zircon, but instead we’re making the most of a cramped Extra.  Sprind is a stand-out here, as discussed, allowing us to pivot from our Link-2s into either of the Roses, which helps cap off an already extensive linear set-up.

While I don’t love that Gem-Knight has fully shirked its prior responsibility to actually play Normal Monsters, this new version of the deck is a true testament to the power of modern midrange lists.  You never really run out of value, have too many good effects to trade 1-for-1 on handtraps, and play just enough non-engine to keep up with combo.  It’s not necessarily exciting mechanically, but the fact that it’s Gem-Knight, after over a decade, is wicked.

There’s more to come with the new Battles of Legend Set!  What other decks from Monster Mayhem have you been enjoying?  Is there a good reason to play pure when Fiendsmith variants exist? Let me know in the comments below!