Fionn mac Cumhaill (SMTV)

Fionn mac Cumhaill is a demon in the series.
Fionn mac Cumhaill is a hunter-warrior in Irish mythology whose given name means "white, bright, lustrous; fair, light-hued; fair, handsome, bright, blessed; in moral sense, fair, just, true." In the Irish stories, Fionn was the posthumous son of Cumhall, leader of the Fianna, by Muirne with many of his followers.