Nordion (ノディオン王国 Nodion Ōkoku lit. Kingdom of Nodion in the Japanese version) is a kingdom of The Dominion of Agustria in Fire Emblem: Genealogy of the Holy War and Fire Emblem: Thracia 776. Hezul's youngest daughter with major Holy Blood married into this house, thus bringing in the major Hezul blood inherited by several Nordion members. Its members were given the Mystletainn in order to protect the Agustria royal family and Hezul's direct descendants.
In Chapter 1, Eldigan comes to Sigurd's aide by preventing Elliot of Heirhein from capturing the player's home castle of Evans.
In Chapter 2, Nordion, comes under attack by troops from Heirhein, but is saved by the timely arrival of Sigurd's forces. However, by the end of Sigurd's tale Nordion, along with the rest of Agustria, has been annexed by the kingdom of Grannvale. Eldigan's son Ares and his mother Grahnye leave for Grahnye's native Leonster, but she dies when it also falls and he is raised by the mercenary Jabarro. Lachesis' children Nanna and Diarmuid also are separated: Nanna goes live with her mother, her father figure (and possible father) Finn and Prince Leif, while Diarmuid goes with Edain, Seliph and the other children to Isaac.
In Seliph's tale, the now-adult Ares returns to Nordion at the end of the game to rule all of Agustria. If his cousin Diarmuid does not inherit a land from his father's side, he will pledge service to Ares and follow him back home. Similarly, his other cousin Nanna will do likewise either if she is not paired up, or if she and Ares are in love.
- Eldigan - The ruler of Nordion who wields the Demon Sword in knightly devotion to any master.
- Lachesis - The Lady of House Nordion who adores her older brother to the point that other men pale in comparison.
- Ares - The son of Eldigan and Grahnye and heir to Mystletainn that joined up with a mercenary captain after his parents passed away. Becomes the king of Agustria after the end of the holy war.
- Nanna - The charismatic daughter of Lachesis who has her mother's graceful bearing.
- Diarmuid - Lachesis' son who has a strong sense of justice.