Geryon is a superboss in the 3D remake of Final Fantasy IV in New Game + mode. He is known as the "Malice of the Four Fiends" and can only be battled on a second or third playthrough. He can be found within the Giant of Babil after the defeat of the four Archfiends, or on Mount Ordeals after the Giant of Babil becomes inaccessible.
Geryon is armed with all of the Elemental Archfiends' signature attacks. These include Scarmiglione's Gas, Cagnazzo's Tsunami, Barbariccia's Maelstrom and Lightning, and Rubicante's Inferno. It is also able to use Curse, Stone Touch, and a powerful physical attack.
Tsunami and Inferno are more powerful than before - especially Tsunami, with which instant death cannot be avoided unless it is turned to absorption. If Kain is the only one left and he Jumps, Geryon will resort to Inferno to heal himself.
An effective way to defeat this boss is to equip all characters with Adamant Armor and Cursed Rings to turn the resistance of the elemental moves into absorption, and to use a Lunar Curtain on the main attackers, or on the whole party, to nullify Geryon's melee damage.
With or without Cursed Rings and Adamant Armor, it is recommended to stall the battle until the last playthrough for the maximum augments. It is a good idea to level-grind the party to at least the higher 70s.
Even if the party has no Adamant Armor Geryon can still be defeated. A full set of Crystal and Dragon equipment (for Kain and Cecil) plus a Cursed Ring will let them absorb everything except Curse and Tsunami. Giving Rydia and Rosa Luminous Robes, Gold Hairpins, and Protect Rings will halve some elemental damage. As for Edge, the only resort is the Protect Ring. Boosting magic defense and magic evasion through equipment will help, as there is no time to cast Shell later on.
If the party is properly protected against status ailments Geryon will be defeated easily, though Curse is not such a huge issue. Kain must have Phoenix equipped, as Tsunami or Inferno can take out the whole party any time. After Geryon takes out the whole party the priority is reviving Kain and restoring his MP as Geryon acts quickly. Before facing Geryon, the player should ensure to have at least 20 Dry Ethers and Elixirs. Rydia and Rosa may also run out of MP mid-battle. If the party happens to survive Tsunami or Inferno, Rosa should restore everyone to full health as soon as possible (dualcasting Curaja is the fastest way).
Having the Darkness augment on any of the three attackers helps greatly. Focus would also be useful, but with Inferno and Tsunami debilitating the party it won't be easy to pull off. In addition to Curse, the attack might miss. Ultima with Limit Break is not really worth it as Geryon doesn't take much damage from the spell, and the turns can be used to heal, buff, or attack instead. The Dualcast augment on Rosa and Rydia is imperative. Omnicasting on Rosa and Fast Talker on Rydia are going to make a big difference.
Cursed Elegy is bad for Kain, Edge, and Cecil—their attacks will miss. The player should use their turns to heal instead, and focus on the magic. While cursed, Edge must be careful about the weapons to throw. Kain should Jump to avoid the Curse and damage as much as possible. It is also a good idea to have Unicorn Horns or Remedies ready for Stone Touch.
Geryon is a demon in Dante's Divine Comedy. Appearing in Cantos 17 and 18, Geryon serves as the beast of transport between the seventh and eighth circles. Its naming follows the trend of christening the Four Fiends after demons depicted on the poem.