Melusine, also known as Tam Lin Lancelot. The most powerful of the three Tam Lins (Fairy Knights) of Morgan le fay, the Queen of Fairies. Although her appareance is one of a tiny white haired girl with yellow eyes, in reality she is a powerful Tam Lin (Fairy Knight) with the power to shapeshift into a Dragon.

As a Lancer class servant, she has two NP:
1. "Innocence Arondight" in her fairy form, a swift spear attack.
2. "Hollow Heart Albion" in her dragon form, a very powerful energy beam