Concept art by Tetsuya Nomura for Final Fantasy VI; while it isn't used in-game, here is where the "Sefilos" name first appears, which would later be adapted to "Sephirot."
Fiend (
Appearances[]
Final Fantasy VI[]
Fiend, along with the rest of the Warring Triad, is one of the three final bosses in Kefka's Tower before facing Kefka himself. Fiend has the highest HP of any singular enemy target in the original release. It attacks with powerful ice-elemental magic, and during the second phase will gain reflect, haste, and image, and use Force Field to grant itself immunity to a random element, making it difficult to hit.
Final Fantasy XIV[]
Sephirot the Fiend (魔神セフィロト, Majin Sefiroto?) is one of the Warring Triad, three primals that were defeated by the Allagan Empire and imprisoned for centuries within the Flagship at the heart of the floating continent of Azys Lla. A statue of his likeness adorns the top, along with statues of the other members of the Warring Triad. He is said to be the primal once worshiped by a tree-like race who summoned him to defend them from an invasion from the Allagan Empire. During the later events of Final Fantasy XIV: Heavensward, his seal begins to weaken and the Warrior of Light must fight him within the depths of 
Containment Bay S1T7.
Final Fantasy Dimensions II[]
Fiend (三闘神・魔神, Santōshin Majin?) was an Eidolon exclusive to the free-to-play version that appeared during a Final Fantasy VI event. It was a water-elemental signet that when summoned dealt damage to all enemies and allies and inflicted stop for a single turn on all enemies.
Pictlogica Final Fantasy[]
Fiend from Final Fantasy VI appeared as a boss.
Final Fantasy Record Keeper[]
Fiend from Final Fantasy VI appears as a boss.
Mobius Final Fantasy[]
Fiend from Final Fantasy VI appeared as a water-elemental mage card, and granted the supreme ability Absolute Zero.
Final Fantasy Trading Card Game[]
Etymology[]
A fiend is an evil spirit or a demon in mythology.
Səphīrōth (סְפִירוֹת, medieval Hebrew form of Sephirot; also spelled Sefirot), is a plural noun in Hebrew; the singular is Sephirah (also spelled Sefira). The Sephiroth are described in the Kabbalah as the manifestations of God that allow Him to manifest in the physical and metaphysical universes. Sephiroth also means "counting" (of numbers).
Majin is a Japanese word generally means "devil". Depending on writing, it can be translated to "devil", "evil", "demon" (魔人), or "demon god" (魔神).