Odin

Odin (オーディン, Ōdin ?) is a recurring Summon Monster in the series. He made his debut in Final Fantasy III and several of his appearances allude to his original encounter.

Most commonly, Odin will appear and slice through enemies with his sword, cleaving them in two and inflicting Instant Death. His ability in most Final Fantasy games is called "Zantetsuken". Other games give Odin the ability to damage enemies normally as well, should they be immune to instant death.

Odin is a demonic-looking knight with horns, a long, curved scimitar and a cape. This progressed to include a lance-type weapon called Gungnir. Odin is always seen on his horse, who takes on demonic attributes as well, such as red eyes and body armor. Sleipnir, Odin's steed in Norse mythology, has eight legs; in some games in the series, Odin's steed has six legs. In Final Fantasy III Sleipnir can be encountered as a six-legged enemy, while Odin's steed is a normal horse.

Final Fantasy IV
The King of Baron takes the role of Odin, having taken the form of a summoned beast after being murdered by Cagnazzo. He can be fought in the basement of Baron Castle after visiting Feymarch and defeating Leviathan and Asura. In the library at the Feymarch it says Odin was undefeated until he was struck by lightning when his sword was raised into the air, which explains his weakness to Lightning.

After defeating him, Odin can be summoned by Rydia. It has a casting time of 2 and cost 45 MP to summon. There is a 50% chance Odin will slay any given foe, but like other instant death attacks, it doesn't work against bosses.

Odin returns as a summon spell for Rydia in the sequel of Final Fantasy IV. There's still a 50% chance that Odin will slice the enemies in pieces at the cost of 45 MP, but like other instant death attacks in the game, it doesn't work against bosses. He is only available during the final battle.

Final Fantasy IV -Interlude-
Odin returns as a summon spell for Rydia in the sequel of Final Fantasy IV. There's still a 50% chance that Odin will slice the enemies in pieces at the cost of 45 MP, but like other instant death attacks in the game, it doesn't work against bosses. He is only available during the final battle.

Final Fantasy IV: The After Years
Odin appears in the Gathering Chapter in a boss battle teamed with Cecil Harvey against Ceodore's party. He is under Maenad's control, but comes to his senses and knocks out Cecil freeing him from Maenad's possession. Odin becomes a summon for Rydia and is also used in a Band move called Iron Flash that grants his power to Cecil, dealing damage to all enemies, and has a chance to inflict instant death.

Odin's attack (upon summon) is Zantetsuken, and functions similarly to the attack from the original Final Fantasy IV.