Nathan

Nathan Mahler is a chevalier, although it is kept a mystery whose chevalier he is.

In Paris
Nathan first appears in Paris at Solomon's mansion where Diva is brought after awakening. He comes from New York and is shown to have planned for a few hundred years ahead.

At New York
Diva is later taken to his house at New York when she becomes pregnant. The other chevaliers frequently visit there and James' body is brought over at his place for treatment. The news of Diva's children is delivered to Solomon by Nathan. After Diva injures Solomon and James' locks him up, Nathan frees his fellow chevalier to go and stage a drama to save Saya.

At Metropolitan Opera
Towards the end of the series, while talking with Amshel, Nathan states that the world exists to showcase Diva's beauty, as was predestined before she was born. When Amshel says Nathan talks like he was there, Nathan implies he was and that before Diva and Saya were born, there was their "mommy" and her faithful chevalier. Nathan later tells Saya that the only thing Diva actually wanted was to have a family. After Diva's death, Nathan asked that Saya kill him, changing into his chiropteran form and allowing Saya to slice through him with her sword, although he is not seen crystallizing.

After the Final Duel
At the end of the series, he is seen in his human form amongst some reporters outside of Van's trial, without explanation of how he survived. It is thought, however, that Nathan may have been the chevalier of Saya and Diva's mother and was therefore not affected by Saya's blood.

Personality
Unlike the other chevaliers, Nathan rarely participates in battle. He is more into living and enjoying his life as a drama. In the opening credits of the final season, Nathan is shown fighting with Saya though they never do in any episode. He plans not only to destroy Saya, but to do it in a "stage" prepared only for the occasion. This desire results in his stopping some battles between Saya and his brothers, much to their annoyance.

Special Abilities
Power: Behind his seemingly effeminate and lackadaisical manners, Nathan may be the most powerful of the chevaliers and will assert his dominance over his younger "brothers" if he feels he needs to. He is the only one of Diva's chevaliers who can make Amshel back down if he chooses to, and the only one Amshel rarely attempts to manipulate.

Speed: Nathan's speed surpasses that of all other chevaliers. He can take away James' locket without the owner even knowing. He goes to rescue James quite a while after Solomon leaves for Christina Island and manages to bring him before Solomon returns. However, it is suggestable that his true speed limit is never shown.

Blood Attribute: Presumably because he is the chevalier of either Saya and Diva's mother or their aunt, his blood is not affected by Saya's when she strikes him down nor does his affect Diva when she drinks it.

Trivia
In the original Japanese series, Nathan often speaks in a manner usually employed by the feminine gender, such as using kashira and wa. In the Sony English dub, this is represented by Nathan speaking in the manner of a stereotypical homosexual character.