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"Gem-Knight" (ジェムナイト Jemunaito) is an archetype that was released in Duel Terminal - Vylon Descends!!. They are used by Julia Krystal in the Yu-Gi-Oh! ARC-V anime.

Their team symbol is a jewel droplet adorned with gold trim and two small, arced points. Its color varies according to the monster or object to which it is attached. All "Gem-Knights" are EARTH, whereas their Type varies between Pyro, Thunder, Aqua, or Rock (with one Fairy as an exception), in keeping with the cardinal elements: fire, wind, water and earth, respectively. "Gem-Knights" are further subdivided into trios: each Type includes a Normal member, a Gemini member, and a Fusion member.

All members of this archetype are named after different minerals. While the four "Gem-Knight" Normal Monsters are shown to be unarmed, the ten Fusion Monsters wield weapons befitting their stats and effects (or lack thereof): "Gem-Knight Aquamarine" uses a bladed shield; "Gem-Knight Ruby" uses a polearm; "Gem-Knight Topaz" uses twin-bladed tonfa; "Gem-Knight Amethyst" carries a shield and what is either a wand or a slim blade; "Gem-Knight Citrine" uses a fire sword, and "Gem-Knight Prismaura" wields a lance and shield. "Gem-Knight Zirconia," on the other hand, is equipped with gigantic fists seemingly to compensate for its lack of effect, "Gem-Knight Seraphinite" uses a lance, and "Gem-Knight Master Diamond" uses a broadsword embedded with gems. "Gem-Knight Lady Lapis Lazuli", which deals effect damage, is depicted without any weapon."Gem-Knight Lady Brilliant Diamond" uses a simple sword.

"Gem-Knight" is the first and, so far, only archetype to boast seven "Polymerization"-styled cards: "Gem-Knight Fusion", "Particle Fusion", "Pyroxene Fusion", "Fragment Fusion", "Absorb Fusion", "Brilliant Fusion" and "Scatter Fusion". Regardless, "Gem Knights" are capable of rapidly Summoning Fusion Monsters with a mere "Gem-Knight Fusion" as its ability grants the user to repeatedly return itself to the owner's hand at the cost of banishing 1 "Gem-Knight" Monster, and with the assistance of "Gem-Knight Obsidian" and "Gem-Knight Lazuli" the user is allowed to recycle "Gem-Knight" Normal Monsters. As a result, the player can Fusion Summon several times from their Extra Deck during the same turn.


A group of warriors endowed with the power of minerals, the "Gem-Knights" value honor above all else and disapprove of battle for the sake of battle. At the provocation of the barbaric "Laval", however, they are forced to take up arms and protect the clans from their wanton destruction. However, the "Steelswarm" begin to invade the surface land, intending to take over. The Gem-Knights join up with the other clans in a temporary union spearheaded by the "Vylons". Along the way, they obtain new powers with which to resist the "Steelswarm". Although the "Steelswarm" are quickly dispatched, conflict is far from over. The "Vylons" decide to exterminate the clans in order to prevent future wars.

The clans once more band together in order to halt the "Vylon", but it is the collaboration between the "Gem-Knights" and "Gishki" to whom credit for their eventual victory goes: "Gem-Knight Pearl" is the downfall of the "Vylon". After the "Vylons" are driven back, the alliances between clans once again dissolve.

The "Gishki" immediately resume their invasion of "Mist Valley", which had been their main objective pre-"Steelswarm". In order to obtain resources from the Valley, the "Gishki" enact a genocide on the "Gusto". The Gem-Knights intervene to rescue the remaining "Gusto".

When the "lswarm" virus begins to spread across the Duel Terminal world, the Gem-Knights join the "Gusto" in a prayer for the "Constellar," a legendary band of divine warriors, to aid them. The "Constellar" may not be strong enough to resist the "lswarm" army alone, as the "Gishki" clan falls to the virus. Knowing this, the "Gem-Knights" fuse into the most powerful Gem-Knight.

"Cairngorgon, Antiluminescent Knight" appears to be a corrupted combination (probably by the "lswarm" virus) of "Gem-Knight Crystal", with parts of "Gem-Knight Zirconia" (right arm and left leg), "Gem-Knight Master Diamond" (left arm and right leg), and "Gem-Knight Prismaura" (damaged head).


Gem-Knight Origin
English Japanese
Alexandrite Alexand Alexandrite
Amber Amber Amber
Amethyst Amethys Amethyst
Aquamarine Aquamarine Aquamarine
Citrine Madeira Citrine
Crystal Crysta Crystal
Emerald Emeral Emerald
Garnet Ganet Garnet
Iolite Iola Iolite
Lady Brilliant Diamond Lady Brilliant Dia Diamond
Master Diamond Master Dia
Lady Lapis Lazuli Lady Lapis Lazuli Lapis lazuli
Lapis Lapis
Lazuli Lazuli
Obsidian Obsidia Obsidian
Pearl Pearl Pearl
Phantom Quartz Phantom Roots Phantom quartz
Prismaura Prism Aura Prism
Ruby Rubyz Ruby
Sapphire Saphire Sapphire
Sardonyx Sanyx Sardonyx
Seraphinite Seraphi Seraphinite
Topaz Paz Topaz
Tourmaline Roumaline Tourmaline
Zirconia Zirconia Zircon

Playing style

The "Gem-Knight" employs rapid Fusion Beatdown strategy (similar to "Elemental HERO" monsters), accomplished with the use the archetype's six Fusion Spells/Traps and a wide array of recycling effects. The "Gem-Knight" Normal Monsters benefit from most Normal Monster support cards, as well as "Gem-Merchant", whose effect resembles that of "Blackwing - Kalut the Moon Shadow". "Gem-Knight Alexandrite" and "Gem-Armadillo" provide excellent search power to facilitate this strategy.

The archetype's key card is "Gem-Knight Fusion", which, apart from granting access to its vast arsenal of powerful Fusions, can return itself to the hand at the price of a "Gem-Knight" banished from the Graveyard. Discard effects can come in handy: cards such as "Phoenix Wing Wind Blast" can remove threats from the field, while also loading the Graveyard to pay this cost. "D.D.R. - Different Dimension Reincarnation" and "Chaos Zone" can re-Summon the "Gem-Knights" banished via "Gem-Knight Fusion", essentially rendering the cost moot and restocking the hand with materials for another Fusion Summon.

Since you can Fusion Summon Gem-Knights using other Gem-Knight Fusion monsters, a Gem-Knight deck can use the effects of Amethyst and Aquamarine to eliminate troublesome Trap Cards and return monsters to the hand, making the field safer for cards like Gem-Knight Prismaura, Gem-Knight Citrine, and Gem-Knight Ruby.

Pairing "Gem-Knight Master Diamond" with the Field Spell "Catapult Zone" is also a good tactic. As the effect of "Master Diamond" allows it to gain 100 ATK with every "Gem-Knight" in the Graveyard, it's prevented from getting destroyed by battle once per turn and send one Rock-Type from the Deck to the Graveyard instead. By feeding in cards such as "Gem-Knight Lazuli", it's ATK will steadily rise over 3000, which causes it to become less vulnerable and it can come in handy when dealing with cards such as "Hieratic Sun Dragon Overlord of Heliopolis".

The release of both Xyz Monsters and "Rescue Rabbit" give "Gem-Knights" another welcome boost. "Rescue Rabbit" can bring out the materials for any "Gem-Knight" Fusion Monsters (or even Xyz Summoning "Gem-Knight Pearl"), and the effect of "Gem-Knight Amber" can return a banished "Rabbit" to the hand for further usage.

With the release of Brilliant Fusion, Gem Knights gained more extremely powerful support that allows them to Fusion Summon using Materials from the Deck, at the cost of the Summoned monster having 0 ATK/DEF. This lead to Brilliant Fusion being played in many Decks simply to Fusion Summon Gem-Knight Seraphinite to obtain an extra Normal Summon (see Engine), but it is also extremely powerful in a dedicated Gem-Knight Deck, especially one built with a few off-archetype monsters to access monsters like Seraphinite. Simply use the Summoned monster's effects, then Fuse it into something even bigger, reviving the Summoned monster later as Brilliant Fusion does Fusion Summon, so the monster was properly Summoned.

With the release of Link Format, Gem-Knights initially suffered, but with the release of Gem-Knight Phantom Quartz, an FTK was discovered using Gem-Knight Lady Lapis Lazuli to repeatedly burn the opponent, Gem-Knight Master Diamond to re-use the effect and Phantom Quartz to recycle monsters while Summoning more Fusion Monsters. This lead to Master Diamond being Limited, and the Deck has since once more faded from the competitive scene, barring Brilliant Fusion, which continued to be a staple for many Decks until it too was Limited due to abuse in "Thunder Dragon" decks. While the FTK is still playable even with these restrictions, it's not considered too serious a threat to the metagame.

However, the Gem-Knight deck is much harder to play after the January 2020 Lists (TCG) listed Brilliant Fusion as Forbidden.

Recommended cards


Despite its speed and flexibility, "Gem-Knights" are not without their multitude of weaknesses. Like the "Evil HERO" series, which relies on "Dark Fusion" and "Dark Calling", the "Gem-Knights" depends upon their "Gem-Knight Fusion" for their usual repeated Fusion Summons (unless other Fusion Spell/Traps like "Pyroxene Fusion" are also included).

One of the most effective ways to cripple these Decks is to activate a card like "Cursed Seal of the Forbidden Spell" or "Armageddon Designator" (the latter if your opponent also just so happens to be using "Gem-Knights" too), which can render it unusable for the rest of the Duel. General anti-Spell support like "Secret Village of the Spellcasters", "Eradicator Epidemic Virus", "Anti-Spell Fragrance" and "Non-Fusion Area" can also damage its play-style, blocking all attempts at Fusion Summoning, leaving the Deck at a severe disadvantage. Cards like "Naturia Beast", "Naturia Exterio" and "Horus the Black Flame Dragon LV8" also pose a serious threat, since they can stop "Gem-Knight Fusion" from working no matter how many times it is returned to the hand.

A more typical concern would be anti-Special Summoning cards such as "Archlord Kristya" and "Vanity's Ruler", which are not as easily dealt with once on the field. Due to the Gemini Monster portion of the archetype, however, support like "Gemini Spark" can be used to handle threats of this nature. The same applies for cards like "Macro Cosmos" or "Dimensional Fissure," so that they will not disrupt the stream of Fusions.

Most "Gem-Knight" Decks that utilize either "Gem-Knight Alexandrite" or "Rescue Rabbit" are also susceptible to "Mirror of Oaths", resulting a possibly loss of momentum. "Skill Drain" can also dangerous, since it will disable most in-field "Gem-Knight" Fusion Monster's effect such as "Citrine", "Prismaura" or "Gem-Knight Seraphinite".

Due to a severe lack of card effect safeguards (save for "Gem-Knight Citrine", which only seals off your opponent from activating card effects when only this card battles) and backrow removal (only "Gem-Knight Amethyst" can bounce face-down Spells/Traps back to the hand and only if it's sent to the GY,) the "Gem-Knight"s can easily be picked off the field by all kinds of card effects. Because of all these threats, general backrow cards that focus on backrow removal (e.g. "Twin Twisters"), card effect protection (e.g. "Royal Decree" and to seal off battle Traps and the "Solemn" series to counter various tactics) and maybe even "Mask of Restrict" to stop "Gem-Knight"s from being Tributed should be a part of many a "Gem-Knight" Deck.

Hand Traps can also spell big trouble for "Gem-Knight"s. "Ghost Reaper & Winter Cherries" and "Ghost Sister & Spooky Dogwood" can particularly intercept the FTK "Gem-Knight" variants, with the former that can banish "Lapis Lazuli" from the Extra Deck and the latter making it harder to achieve a FTK by increasing the opponent's LPs for every "Gem-Knight" Special Summon, (notably, "Alexandrite", "Crystal" and most "Gem-Knight" Extra Deck monsters have exactly or over 2000 ATK, providing big LP boons.) "Debunk", "Called by the Grave" and "Mind Drain" can put checks on these hand effects.

The introduction of the Extra Monster Zone severely weakened the Deck's ability to Fusion Summon multiple "Gem-Knights" at once, though the introduction of "Gem-Knight Phantom Quartz" somewhat mitigated this. This blow to the archetype became moot on April 1, 2020, when Fusion, Synchro and Xyz Monsters were once again allowed to be Special Summoned directly to Main Monster Zones from the Extra Deck.


  • This archetype appears to be based on the "Elemental HERO" archetype, since a few of their monsters' poses are based on the poses of the "Elemental HERO" monsters.[1][2][3]
    • In context of the "gem" theme, this archetype also appears to be based on the "Crystal Beast" archetype, since Jaden Yuki and Jesse Anderson were friends in the anime (who used an "Elemental HERO" Deck and a "Crystal Beast" Deck, respectively).
  • "Gem-Knight" monsters are all of one Attribute (EARTH), yet have a variety of Types, whereas the anime-based "Elemental HERO" monsters are all of one Type (Warrior), but of different Attributes.