Kaiou Poseidon

Kaiou Poseidon (海王 ポセイドン, lit. Sea King Poseidon) is a Keshin.

Inazuma Eleven GO

 * Namikawa Rensuke
 * Guel
 * Shaza Sabaki
 * Tsunami Jousuke

Inazuma Eleven GO 2: Chrono Stone

 * Namikawa Rensuke
 * Rodeo
 * Shaza Sabaki

Inazuma Eleven GO Galaxy

 * Namikawa Rensuke
 * Rodeo

Hissatsu
Inazuma Eleven GO=
 *  [SH] Heavy Aqua Lance
 *  [SK] Kick Force 5


 * -|Inazuma Eleven GO 2: Chrono Stone=
 *  [SH] Heavy Aqua Lance
 *  [SK] Kaze no Inori


 * -|Inazuma Eleven GO Galaxy=
 *  [SH] Heavy Aqua Lance
 *  [SK] Kick Force X

Anime
It appeared in Episode 20, in the Holy Road Kanto Region preliminary finals against Raimon. Namikawa scored a goal against Raimon, but at the end it was overpowered by Majin Pegasus.

Afterwards, this Keshin was seen again in Episode 32, but only in a flashback where Tenma, Shinsuke, Shindou, Aoi, Akane and Midori were thinking of the past matches. It was not used in the episode itself.

Info (Chrono Stone)
It reappeared later in Chrono Stone in Episode 41, used by Rodeo. He shot using Heavy Aqua Lance, but it failed against Sangoku's Shin God Hand X.

Trivia

 * Poseidon was the god of the sea, and, an "Earth-Shaker of the Earthquake" in Greek mythology.