Like his other appearances, Gilgamesh has a gray complexion, red/orange armor, and as many as eight arms in which he holds an arsenal of different weapons.
Gilgamesh was one of several espers captured by the Gestahlian Empire during their first raid on the esper world. The captive espers were taken back to the Magitek Research Facility at Vector, and for sixteen years they were experimented on and had their magic drained to develop the Empire's Magitek army.
Shortly before the Returners infiltrated the facility and shut it down, Gilgamesh and three other espers escaped. In the World of Ruin, Gilgamesh was at Dragon's Neck Coliseum when the party bet a rare sword, Excalipoor. Desiring the sword for himself, Gilgamesh attacked them but was defeated. He then entrusted his magicite to the party.
Gilgamesh costs 99 MP to summon, and has varying effects depending on which of his three swords glow when he is summoned. If the left sword glows, Gilgamesh will use Excalibur, dealing Holy-elemental damage to all enemies with a spell power of 120; if the middle sword glows, Gilgamesh will use Masamune, dealing non-elemental defense-ignoring damage to all enemies with a spell power of 99; if the right sword glows, Gilgamesh will use Excalipoor to deal one point of damage to all enemies; and if all three swords glow, Enkidu will attack all enemies, dealing non-elemental defense-ignoring damage to all enemies with a spell power of 200. Gilgamesh gives a +2 boost to Strength at level up.
If acquired early in the World of Ruin, Gilgamesh can be a very powerful esper; his three damaging abilities besides Excalipoor are all stronger than Bahamut and can deal massive damage to enemies. However, he only has a 75% chance of doing one of his heavy-damage attacks, making him unreliable. His +2 Strength bonus is also useful to allow the player to train stats, especially as several of the first characters the player will recruit in the World of Ruin use Strength as their primary damaging stat.
Gilgamesh teaches the valuable Quick spell, the only esper to do so other than Raiden, but Gilgamesh can be acquired much sooner. The Valor spell can be very useful for parties focused on physical characters, but is useless to mages.
To face Gilgamesh, the player must purchase Excalipoor from the Jidoor Auction House after speaking to an NPC in the town that mentions a "rare sword" for bid. Betting Excalipoor at the Coliseum pits the player against an Onion Dasher. After the battle, Gilgamesh challenges the entire party. Despite taking place in the Coliseum, Gilgamesh is faced in a normal battle with the player able to control their party.
Behind the scenes
This incarnation of Gilgamesh is specifically based on his appearance in Final Fantasy VIII, where Gilgamesh uses one of four random swords to attack. In this game he does not have the Zantetsuken, and calls Enkidu in place of using that sword. His behavior as a boss is based on his boss battles in Final Fantasy V; he uses many Blue Magic skills and when weak casts Protect, Shell, and Haste on himself, then uses Jump attacks.
Gilgamesh is the main character of the Epic of Gilgamesh, an Akkadian poem considered the first great work of literature. He is a demigod with superhuman strength who builds the walls of Uruk to defend his people and travels to meet the sage Utnapishtim, a survivor of the Great Flood.
Gilgamesh is believed to have actually existed by many scholars. It is estimated he lived sometime between 2800 and 2500 BC. The Sumerian King List claims Gilgamesh ruled the city of Uruk for 126 years.
Gilgamesh in Final Fantasy is also based on Benkei, a famous character in the Japanese mythologies and chronicles of the Genpei War. A powerful warrior monk said to have personally defeated 200 men in every battle he engaged in and said to have had the strength of demons, Benkei's introduction sees him set out to collect 1,000 weapons, and to this end he posted himself at Gōjō Bridge in Kyoto and challenged every warrior who attempted to cross. On his 1000th duel Benkei was defeated by Minamoto no Yoshitsune, the only defeat he had ever known, and became his faithful retainer throughout the rest of his life.
From the story of Benkei, Gilgamesh takes his preference for the naginata (Benkei's traditional weapon as a monk), his penchant for fighting on bridges, his collecting of weapons from enemies he defeats, and his friendship with the player's characters who defeat him. Benkei's devotion to Yoshitsune is the basis for Gilgamesh's association with Genji equipment—the Minamoto Clan is also called the Genji Clan, using the alternate pronunciation for the Chinese characters for mina and moto, gen and uji, respectively. Gilgamesh's face paint is based on traditional kabuki actors, for which Benkei is a popular character to portray.