Tethra possessed a magical harp and became a spectral ruler. He represents the afterlife’s allure and the Fomorians’ enduring presence. Poets reference Tethra to explore the sea as a realm of the dead, the persistence of enemies beyond death, and the haunting power of music in the underworld.

Tethra is a Fomorian king killed in the Second Battle of Mag Tuired; fallen warriors go to his hall in the Otherworld. Students should note Tethra as an example of the noble adversary—where even enemies provide honorable afterlife. His hall becomes a place of warrior rest, showing shared heroic ethos across lines. Poets reference Tethra to explore the afterlife of heroes, the paradox of enemy honor, or the universality of martial valor—especially in elegies or works about the dignity of the fallen.