Main heroine, she released Arawn from his slumber. She takes a liking to Arawn instantly after she was saved by him, and decides to marry him. Riannon's true (magic) name Primula, she is the direct descendant of the elf king Pwyll, mixed with human genes since she is only partially elf. She, like a her brother, think simply as well, which sometimes Arawn calls them 'foolish brother and sister' due to some foolish things they do.

[Source: Wikipedia]

Riannon is adept at magic, particularly healing spells. Her naturally sunny personality as well as her skill in the kitchen, endear her to friend and foe alike. The red sash she wears can only be given to the man she is to marry, which is also the mark of the Gael clan chief. She gives this sash to Arawn as thanks for saving her from mind-control, and to keep her brother Aurthur from attacking him, though also because had romantic feelings for him from the moment she saw him.

The first of Arwan's three wives in the anime, and the first of five in the PC game, Riannon doesn't seem to mind Arawn having multiple wives, taking such things in stride.