Four Fiends

The Four Fiends  are a group of recurring enemies and characters in the Final Fantasy series. Are often associated with the four elemental forces - fire, water, wind and earth. They can be seen as counterbalances to the four Crystals, as the Four Fiends often seek to subvert the influence the Crystals have on the world.

Final Fantasy
The Four Fiends are demons that serve Chaos. They sequester themselves in caverns around the world to drain the Crystals of their energy. Each are defeated by the Warriors of Light, only to be fought again in the final dungeon, the Chaos Shrine, before the final battle with Chaos. In the Dawn of Souls and the 20th Anniversary version, the Four Fiends of Final Fantasy IV can be fought in the extra Soul of Chaos dungeon, Hellfire Chasm.

Final Fantasy III
The Guardians of the Dark Crystals are creatures sent by the Cloud of Darkness to guard the Dark Crystals and kill the Warriors of Light in the World of Darkness. The Warriors of Light search for the Warriors of Darkness to weaken the Cloud of Darkness and find the Dark Crystal. Each Guardian represent a element and guard a dark crystal of its respective element. Eventually all of the guardians and the Cloud of Darkness are defeated by the combined power of both warriors of light and dark.

Final Fantasy IV
The Four Archfiends or Four Fiends of the Elements play a major role in this game, as they act as go-betweens between Golbez and Zemus, keeping tabs on Zemus' control of Golbez while serving the latter as minions. They are Scarmiglione of Earth, Cagnazzo of Water, Barbariccia of the Wind, and Rubicante of Fire. Cecil's group has to fight each one once, and then he must fight all four together near the end of the game inside the Giant of Babil. They can also be fought as a single entity called Geryon in the DS remake.

Final Fantasy IV: The After Years
The Four Archfiends of Final Fantasy IV return in the sequel, as do the original Four Fiends from the original Final Fantasy.

Final Fantasy IX
Referred to as "The Chaos Guardians," they are based on and directly named after the original Four Fiends of Final Fantasy: Maliris, Tiamat, Kraken, and Lich. Similar to the Chaos Guardians are the four guardians of the elemental shrines on Gaia that seal the entrance to Terra. The four of them appear very similar to the Chaos Guardians and bear the same elemental affinities. Only Lich, the Earth Guardian, is fought by the player (using Zidane and Quina), while the other three are killed off-screen (Maliris by Freya and Amarant, Tiamat by Vivi and Steiner, and Kraken by Garnet and Eiko). In addition, only Kraken goes unseen prior to the final events of the game.

Kuja later creates the four of them from the memories of the Crystal in Memoria to try and kill Zidane and his friends as they track down Kuja within Memoria. Crystal palette swaps of the four are fought in the Crystal World, the final area of the game.

Final Fantasy Tactics Advance
An elite group of the Red Wings known as the Falgabirds appears. It consists of four powerful monsters representing the original Final Fantasy's four fiends:
 * Lich, who appears as a boss Zombie;
 * Marilis, who appears as a boss Lamia;
 * Kraken, who appears as a boss Ice Flan;
 * Tiamat, who appears as a boss Thundrake;

The Final Fantasy Legend
The Four Fiends of The Final Fantasy Legend are servants of Ashura, and through him, the Creator. They are based on the Four Symbols of Chinese astrology and are given the Japanese names for those symbols. Each either guards or seeks a Sphere of their associated mythological color, which controls access to The Tower. When the party confronts Ashura, he tempts them with control of the four major worlds, essentially offering them the role of Fiends. When the party climbs the outside of The Tower, they face the Fiends a second time, each of who drops a single piece of top-tier Meat for the party's Monsters.
 * Gen-Bu, Black Tortoise of the South, who has sundered the Hero Statue to guard the Black Sphere.
 * Sei-Ryu, Azure Dragon of the East, who holds half of the Blue Sphere.
 * Byak-Ko, White Tiger of the West, who searches for the White Sphere from a flying fortress.
 * Su-Zaku, Vermillion Bird of the North, who has leveled the fourth world single-handed and guards the Red Sphere.

Final Fantasy Mystic Quest
The Vile Four are the servants of the Dark King and attack the resting place of the Crystals to drain their energy. They are named Flamerus Rex, Ice Golem, Dualhead Hydra, and Pazuzu.

As in Final Fantasy, stronger versions of these foes are fought in the final dungeon as palette swaps, but bear different names: Skullrus Rex, Stone Golem, Twinhead Wyvern, and Zuh.

Final Fantasy Dimensions
The Four Generals are the commanders of the military of the Avalon Empire. Baugauven, who controls fire, is a shrewd man who invents his own powerful techniques. Asmodai, who controls earth, is able to exude a miasma that renders him invincible. Styx, who controls water, is also a witch with knowledge of powerful curses. Vata, who controls wind, is the youngest of the four, and accidentally gains the power of the Dragoon. Their superiors are the four Divine Generals, who possess the elements of thunder, ice, light and darkness.

Dissidia Final Fantasy
Both the Four Fiends from the original game and the Archfiends from Final Fantasy IV appear in Dissidia as summons. The Four Fiends all have effects involving timers that activate an effect when it reaches zero, while the Archfiends activate in response to the opponent's summon. The two groups share effects based on their ranking of power in their original games - Lich and Scarmiglione reduce the opponent's Bravery to 0, Marilith and Cagnazzo freeze the opponent's Bravery, Kraken and Barbariccia swap the Bravery of both characters, and Tiamat and Rubicante triple the summoner's Bravery.

The Four Fiends are shown in portraits in the corners of the Old Chaos Shrine arena. Garland's original four HP Attacks, as well as the forms his sword takes, are based on the Four Fiends - an axe form for Earthquake, twin swords for Blaze, a chain flail for Tsunami, and an extended lance for Cyclone. The bonus sample voices that the player can unlock for Garland in the PP Catalog are of him speaking the names of the Four Fiends, as well as Chaos.

The Archfiends have an equipment set named for them that gives the "Elemental Archfiend" combination - Scarmiglione's Fang, Barbariccia's Wristlet, Rubicante's Cowl, and Cagnazzo's Carapace.

Each of the Archfiends and Four Fiends has a respective player icon depicting their debut appearance from their games' original releases.

Dissidia 012 Final Fantasy
In Dissidia 012, the prequel to Dissidia, the Archfiends now also appear as tutors for the in-game manual in the Labyrinth.

Etymology
The original Japanese name, the, is a reference to the four gods from Buddhist faith. Shitennō is also used to refer to a group of four leaders in a given field, i.e "The Big Four" or "Quadrumvirate".

Trivia

 * A recurring trait between the Earth-elemental "fiends" is their affinity to status ailments and/or Death: Lich, Scarmiglione and Flamerus Rex are Undead, and Scarmiglione and Asmodai use powerful debuffing abilities.