- —Alfin's intro quote, Trails of Cold Steel III
Alfin Reise Arnor is the crown princess of the Erebonian royal family, and Olivert Reise Arnor's younger half-sister in the The Legend of Heroes: Trails of Cold Steel trilogy. She attends the Saint Astraia Girls' School located in the capital city with her best friend, Elise Schwarzer.
She has long, wavy blonde hair and an angelic disposition. She is very popular amongst the people of Erebonia, and considered to be one of its "national treasures", the other being Cedric.
Alfin was raised as a eccentric noblewoman to be courteous around others. When with her close friend Elise, she can be a bit of a prankster. Nevertheless, she acts as a supportive role around her best friend Elise and the Courageous resistance, often acts as support for her kind, timid twin brother, Cedric. She recognises that her friend Elise has a crush on her adoptive brother, Rean and often tries to push them towards each other, though Rean is oblivious.
After the Civil War, she advances to the high-school division like Elise. However due to the dramatic changes after the war, she becomes deeply anxious about her twin brother's well-being and the explicit toleration from her older bother and the Vander Family.
- The name, Alfin, can mean "King" in Eastern languages.