Elffin is a playable character in Fire Emblem: The Binding Blade. He is a bard who fights for the rebellion in the Western Islands. He joins Roy's army when they save the villagers from the corrupt Etrurians and their hired bandits. In the army, he can play the role of a fortune teller or of a Bard depending on the route.
He originally hides his true identity from Roy as a bard, because he is really the prince of Etruria, Mildain, that was said to have died by falling from horseback. In reality though, he was hit by a poisonous arrow and was nearly assassinated. The poison still causes him to be blind for moments. He only reveals who he really is to a few people, including Douglas and Klein. Cecilia recognizes him because of a scar on his right shoulder.
When they were younger, Klein was his best friend; he was a bit older than Klein and he wanted him to be his brother, but Klein refused, for he had wanted to be his knight. Elffin is also very effeminate, confusing Fae (in their support conversations) who believed he was a girl since he was 'pretty'.