Much like the Fiends of Chaos from Final Fantasy I, of which they are likely inspired, each Archfiend controls one of the four classical elements: Earth, Water, Wind, and Fire. They are all named after a demon from Dante Allighieri's famous Inferno poem, one of the Malebranch guarding the demon Malebolge from the Eight Circle of Hell.
Each one of them is more powerful than the previous, with Rubicante being as powerful as Golbez himself. This and the fact that Zemus resurrects them to stop the heroes strongly hints that they are in fact under the control of Zemus instead of Golbez, and obey him by proxy. It might even have been Zemus who send them to the sorcerer. Still, they have immense respect and loyalty to Golbez, who in turn is quite close to them, and still empathizes with them even after being freed from Zemus' control.
They are implied to be in fact Forces of Natures and personifications of the elements, corrupted and turned into their current demonic self by Zemus, much in the same way as Golbez himself.
ScarmiglioneThe Archfiend of Earth, who goes by the title of the Blighted Despot. He first appears as a crouched, hunchbacked humanoid in a hooded robe, but is true form, which he can only assume after "dying" appears as a twisted, half-rotting undead with four huge, tusk-like protruding bones. He makes hissing sounds and speaks with a hissing voice, and appears to be quite scorned by his fellow Archfiends.
Golbez sends him to Mount Ordeals to kill Cecil, who went to the mountain to become a paladin. Cecil, who was along with Palom, Porom, and Tellah, is intercepted by Scarmiglione in the peak of the mountain. Cecil fights him and his undead minions, but easily defeats him. However, Scarmiglione lost to him on purpose, because he could only use his true power after being killed, being an undead himself.
Resurrected, he attacks Cecil from behind with all of his power, but is defeated again and he falls off the bridge to his death.
CagnazzoThe Archfiend of Water, who goes by the title of the Drowned King, who looks like a turtle-like monster. Under the orders of Golbez, he killed the King of Baron and shape-shifted as him to impersonate him. He orders the Red Wings, Baron's powerful airfleet, to retrieve the crystals for Golbez. He is regal, but haughty, contemptous and arrogant, despises Holy Powers and hates being bested.
Baigan, a Red Wings officer whom Golbez later turned into a monstrous underling, alerted him that Cecil Harvey, the primary protagonist and commander of the Red Wings, was questioning him, so he demoted Cecil from his post and ordered him to deliver a ring to Mist Village. When Kain Highwind tries to argue, the fake king oders him to accompany Cecil. The ring was actually a Bomb Ring, which destroyed Mist Village. After Cecil becomes a paladin in Mount Ordeals, he uses an underground tunnel to return to Baron and confront the king.
Cecil finds his friend Yang on the pub, who had suffered from amnesia and been brainwashed by Cagnazzo, but manages to make him recover consciousness. Along with Yang, Palom, Porom and Tellah, he enters the castle, but is confronted by Baigan, having to kill him to gain access to the throne room. There, Cagnazzo reveals his true form and attacks Cecil, but is killed. As he was about to leave, Cagnazzo uses his last strength to activate a trap in the room, making the walls move to smash them all. Palom and Porom make the ultimate sacrifice and turn themselves into stone to stop the walls.
The Archfiend of Wind and the sole female among them, who goes by the title of the Empress of Winds. She looks like a scantily clad, winged woman with long blonde hair, somehow similar to a harpy. She is flirtatious and sadistic, and appears to have some feelings for Kain Highwind.
Barbarriccia is in charge of the floating Tower of Zot, Golbez's hideout and main headquarters. There, she she was ordered by Golbez to keep Rosa, Cecil's girlfriend, captive, in order to force Cecil to retrieve the Earth Crystal for them.
Using the Master Engineeer Cid Pollendina's last airship, Cecil enters the floating tower after Rosa and Golbez, so Barbariccia sends her underlings, the Magus Sisters, after him. After they are defeated, Cecil confronts Golbez and Kain, but then Tellah steps in front of them to confront Golbez alone. He uses the forbidden spell Meteor, grievously wounding his foe at the cost of his life, and lifting his mind-control of Kain.
After Golbez escapes, Kain guides Cecil to where Rosa was trapped, saving them from a falling blade at the last second, but as they try to leave Barbariccia stops them, infuriated at Kain's betrayal. Cecil and Kain fight together and defeat Barbariccia, but then the tower starts to fall, so Rosa teleports everyone out.
RubicanteThe Archfiend of Fire, who goes by the title of the Autarch of Flame. He is their leader and the most powerful of them. He looks like a tall, red-skinned, devil-like humanoid wrapped in a cape. While cruel, violent and evil, he is quite friendly and genuinely respectful with the protagonists. He admires courage and strives for fair fights, but dismisses hope and teamwork as weaknesses, leading to his downfall.
Rubicante is in charge of the Tower of Babel, a gigantic tower linking the surface of the world and the Underworld, built by the Lunarian civilisation from the Second Moon. With the help of the Dwarf King Giott, Cecil and his group invaded the tower from the Underworld entry. Once inside, they see Rubicate speaking with Dr. Lugae, his underling, leaving him in charge while he went to the Kingdom of Eblan in the surface.
Back on the surface, Cecil and the rest went to Eblan only to discover that Rubicante wiped out the country, forcing the survivors to retreat to a nearby cave. Inside the cave, they witness the prince of Eblan, Edge, challenging Rubicante. Rubicante easily defeats him, but spares his life, as he sees it would be a waste to kill a warrior with such potential. Cecil convinces Edge to join his group, so they can defeat Rubicante together.
They make it to the top floor, where Rubicante awaits for them, however, he does not want to fight, telling Edge he would not reach his full potential with anger alone, and thus he was not a worthy opponent for him. Edge gets furious, releasing all of his strength and challenging Rubicante. As a chivalrous warrior, Rubicante heals them all, so they can fight him with all their might. The group defeat him, so he praises them for their efforts, wishing them good luck.
Final Fantasy: The 4 Heroes of Light
Final Fantasy Crystal Chronicles: Echoes of Time
Final Fantasy Crystal Chronicles: My Life as a King
Final Fantasy Dimensions
Final Fantasy Mystic Quest
Final Fantasy Tactics