"Infernity" (インフェルニティ Inferuniti) is an archetype of DARK monsters used by Kalin Kessler in the Yu-Gi-Oh! 5D's anime and manga. They consist of monsters whose effects activate when a player has no cards in hand. In episodes 33 - 35 in the dub of Yu-Gi-Oh! 5D's, the archetype was referred to as "Infernalty".
"Infernity" has two primary themes within their artworks; members originating from the anime have a more Wild West-inspired aesthetic, as seen with "Infernity Avenger" and "Infernity Randomizer" for cowboys and the likes of "Infernity Archfiend" and "Infernity Mirage" for Native Americans. Meanwhile, the manga members much more closely resemble chess pieces akin to the early "Archfiend" monsters, namely "Infernity Patriarch" and "Infernity Knight". Fire is also a commonality shared by members of the archetype and as their name implies, are generally demonic in appearance.
"Infernity" is a portmanteau of the words "Infernal/Inferno" and "Infinity".
The archetype has a play-style focusing on having an empty hand, with in-theme ways of emptying it to make their plays. This can make cards that force discards a bonus for the Deck even against an archetype that would focus on doing so. They also possess strong Special Summon capabilities, allowing them to take advantage of multiple mechanics. A key member of the Deck is "Infernity Archfiend", able to Special Summon itself when drawn into an empty hand and allowing for a search upon doing so. As such, having it in your starting hand can dampen the usefulness of the card though there are workarounds. "Infernity Wildcat" can help with getting monsters into the GY to allow one to get going as it gets rid of a fellow "Infernity" to Special Summon itself, and as a Tuner allows for easier Synchro Summoning on top of being able to modify its own Level by banishing a comrade from the GY, while "Avenger" requires a monster to be destroyed. One could use this with "Infernity General", who in turn banishes itself to revive 2 Level 3 or lower "Infernity" monsters which could also set up Xyz Summons. "Infernity Beetle" is another Level 2 Tuner which Tributes itself to Summon additional copies from the Deck while you have a bare hand, adding to swarming capabilities. Another helpful member is "Infernity Necromancer", who can immediately go into Defense Position with a decent 2000 DEF and Special Summons more resources from the GY, which can be combined with "Infernity Mirage" for swarming and recovery though note "Mirage" itself cannot be Special Summoned. "Infernity Conjurer" revives itself and, while your hand is empty, lowers the ATK of opposing monsters by 800. "Infernity Dwarf" simply grants your monsters piercing battle damage which may be of some use, whilst "Infernity Beast" shuts down Spells/Traps when it attacks. "Infernity Destroyer" sports a decent 2300 ATK and can deal an additional 1600 effect damage when it destroys a monster, conversely "Infernity Guardian" cannot be destroyed by battle or card’s effects while face-up which can help with playing defensively. "Randomizer" allows for some draw-power while also inflicting burn damage if it draws a monster but can also burn you for 500 damage if anything else is drawn. "Patriarch" relies on being the only card in your hand to Special Summon itself, and can banish itself from the GY to save your cards from destruction while "Knight" can empty your hand 2 cards at a time to revive itself. "Infernity Archer" simply attacks directly. In terms of the Extra Deck, the Synchro Monster "Infernity Doom Archfiend" can negate any face-up card's effects and on a bare-bones hand, can also destroy it while also doubling any battle damage it inflicts. It also grants any DARK Synchro Monster up to 2 attacks each Battle Phase. "Infernity Doom Dragon" can target and destroy a monster before inflicting half its ATK as damage but won’t be able to attack.
In terms of Spells and Traps, a staple card is "Infernity Launcher" as it can empty the hand faster and bring back 2 of your monsters by sending itself to the GY. Combined with "Wave-Motion Inferno" this can quickly power up your monsters and start off strong. "Infernity Paranoia" can Tribute your monsters to Summon another from the Deck or GY but its effects are negated as a result, and must have different name but the same Level as the Tribute. "Paranoia" can also recover resources during the next turn after it was sent to the GY. "ZERO-MAX" helps with reviving your monsters and can clear the opponent's field of monsters with equal or lower ATK to boot. "Phantom Hand" is a Continuous Trap that allows its controller to banish their entire hand face-down which could be a counter in a pinch against Decks that would lose you the game. "Infernity Suppression" can negate a monster's effect and inflict burn damage, making it valuable with the fact it can be activated the turn it was Set if you have an empty hand. "Infernity Barrier" on the other hand, is a Counter Trap that can negate anything while your hand is lacking, making it a staple. "Infernity Reflector" empties the hand when your monster is destroyed and revives it before inflicting 1000 damage.
"Void Ogre Dragon" is a useful Synchro Monster for the Deck (and was even used by Kalin Kessler in the manga), providing a big 3000 ATK beatstick who can negate and destroy any Spells/Traps the opponent would use. "Charge Into a Dark World" can resurrect practically any of the Main Deck members before emptying your hand, making it a perfect fit. "Dark World Dealings" might also be of use as it can draw a card while also providing your GY with resources. "Cherubini, Ebon Angel of the Burning Abyss" is also helpful as it can accomplish getting monsters like "General" ready for later. "Hundred Eyes Dragon" is an extremely useful card, able to continuously copy the effects of your monsters in the GY to get more mileage out of them, especially the likes of "Mirage".
Despite their power, "Infernity" can be quite the glass-cannon as their reliance on having no hand can keep the player from using their effects if unable to discard. Cards like "Ash Blossom & Joyous Spring" and "Effect Veiler" can also harm the Deck significantly as shutting down the effects of "Archfiend" can be a death sentence. Cards like "Dimensional Fissure" will also stop it dead in its tracks. Another, arguably greater flaw is the Deck's reliance on an explosive start which can quickly drain resources and make it vulnerable if unable to go in for a quick kill.
- The Deck has great symbolance with its user in the anime, Kalin Kessler's mindset. Kalin believes he must pay for his wrongdoings, and "fate" determines whether or not he will win. He largely determines his win or loss off his topdecks, as he must have no cards in his hand when dueling. This can be well said about the play-style of "Infernity", as it is an almost guaranteed win if you draw a good hand, but you will likely lose very quickly if you draw a bad hand and are unable to empty it fast enough, unless you topdeck an extremely lucky card such as "Infernity Archfiend".
- In the manga, Kalin sometimes refers to his monsters as "Purgatory" monsters rather than "Infernity".
- The handless effect of the "Infernity" archetype is identical to the "Hellbent" effect of the "Rakdos" related cards from Magic: The Gathering.
- Additionally, the "Rakdos" cards use Red/Fire and Black/Darkness mana, while "Infernity" monsters are DARK monsters and their artwork generally depicts them in some fiery location or using fire.
- "Infernity" is notorious for its ability to take huge advantage of new Summoning types and mechanics.
- While initially doing little of note, the archetype quickly made great use of "Brionac, Dragon of the Ice Barrier" pre-errata.
- During the Xyz era, the Deck was able to abuse both "Leviair the Sea Dragon" and "Lavalval Chain" to easily keep "Hundred Eyes Dragon" in a deadly state, even copying the effects of "Mirage" to keep the game in their favor.
- During the Pendulum era the archetype favored using a combination of "Performapal Skullcrobat Joker", "Monekyboard" and "Lizardaw" to easily abuse Pendulum Summoning, short-lived as it was.
- When Link Monsters were introduced, "Infernity" was almost immediately using a combination of "Firewall Dragon", "Summon Sorceress" and "Knightmare Goblin" to rise up once again prior to the cards in question being banned.