Phenel

Feynail Tsuleu-Arde Corwen is Rayneshia and Iselus' father and Duke Serjiad Corwen's son-in-law. Feynail is married to Sarariya, Serjiad's daughter and Rayneshia's mother. Feynail and Sarariya have three children: Risselthea, Rayneshia, and Iselus.

Prior to the Catastrophe
Feynail came from an earldom in Maihama, and was adopted by his wife's family when he married her. The two met when Sarariya became involved in the world of politics, and she instantly fell in love with him. Since Serjiad has no son, Feynail and Sarariya's son, Iselus, will be Serjiad's successor.

Return of the Goblin King arc
Feynail makes his only appearance during The Return of the Goblin King, when he is informed of the sudden appearance of hordes of goblins that far outnumber the forces of the People of the Land. He tells his daughter to remain at the Ancient Palace of Eternal Ice with her grandfather, while he and the other nobles plan for the coming invasion.

Homesteading the Noosphere arc
Neither Feynail nor Sarariya appear during this arc, despite the focus on Maihama. They are mentioned, however, during one of Serjiad and Isaac's talks, where Serjiad informs the Adventurer that Iselus would be his successor.

Trivia

 * The anime has Feynail call Duke Serjiad his father, whereas he is Serjiad's son-in-law in the light novel. In season 2, this mistake is rectified after Isaac asks Serjiad about "his son".