Eochaid is a son of Mannan and has lived almost since the beginning of time. He is much older than the Wild Hunt, and much more powerful. In the old days he hunted giants and monsters with his siblings, but chose to serve the Unseelie King as one of his assassins.
In 2012 Eochaid and his siblings were sent after the Blackthorn family to retrieve the Black Volume of the Dead for the Unseelie King. Eochaid went after Kit Herondale and the twins Ty and Livvy Blackthorn in London, along with Etarlam and Karn.
In London Eochaid fought Kit and the twins alongside his siblings until the fight was interrupted by Gwyn ap Nudd and Diana Wrayburn. He was shocked when he felt his brother Fal die and announced his death to Karn and Etarlam. He tried to attack Gwyn after the leader of the Wild Hunt offered to sound the horn for Fal, but was stopped short by Diana. He left with his brothers to join their siblings in Cornwall.
Eochaid later joined his surviving siblings in attacking the London Institute. He appeared to know Kieran and fought him, then Mark Blackthorn, until Annabel Blackthorn appeared and threatened to reveal the Unseelie King's name. Eochaid then retreated with his family.
Like the rest of the Riders, Eochaid is arrogant and cruel, and confident in his abilities.
Eochaid has a fine-boned, cruel face like an eagle, and long bronze hair. He wears a bronze half mask as well as a bronze cloak and armor etched with designs of waves and the sea.
- Longevity: As a Rider of Mannan, Eochaid is very old and has been alive for thousands of years.
- Enhanced Strength/Speed: Eochaid is able to move incredibly fast and deal heavy blows.
- Invulnerability: Eochaid is immune to most magic, such as seraph blades, and cannot be killed by conventional means.
- Lord of Shadows (first appearance)
Eochaid is an old name of Irish origin, used by many legendary figures.