Solomon Goldsmith was a medical doctor who was introduced to Diva by Amshel in 1917 during the Russian Revolution.At this time, he became one of her chevaliers, after which he wears only white clothing as a symbol of his being Diva's chevalier because it was what he was wearing when he met her. At the time, he wanted to free himself from seeing humans kill each other, but afterwards, he started seeing humans as insignificant and beneath him. As time passed, he realized the world of the chiropterans are just as full of war as the human one.

Although he agrees that Saya is now a threat to him and his partners, he harbors strong feelings for her and regularly tries to protect her, despite his brothers' intentions to destroy her. He was first introduced to her as a delightful young man at the ball in her Vietnam school, and danced his only dance with her. After the dance he apologized, telling her that he had only asked her as she was the only girl who wasn't staring at him. He did not discover who she was until later. He later saves Saya from James and says he wishes to protect her because he is in love with her

Solomon's love for Saya only continued to grow as the series progressed, bringing him into conflict with his chevalier brothers and with Diva. Solomon eventually decides that he simply cannot kill Saya or continue to support Diva's efforts to do so, and wants to live with her as someone who loves her. While Amshel thinks Solomon's love for Saya is just part of his instinct as a chevalier, Solomon disagrees and knows he loves Saya as himself, Solomon Goldsmith. Diva disowns him and tells him to do whatever he wants, and even says he should go make babies with Saya. As a sign of his no longer being a chevalier, Solomon stops wearing his signature white suits, instead switching to black ones.

Solomon kidnaps Saya after saving her from Amshel. He confesses his love for her and asks her to marry him, but Saya gently rejects him. Afterwards, Solomon briefly sinks into a depressed mood. Nathan visits him and takes him to visit Diva and the babies, but Solomon uses the opportunity to try to kill her. Diva easily defeats him and he is imprisoned at the mansion. James taunts him by promising to kill Saya and bring her head in front of him. Amshel tells Nathan to kill him, but Nathan frees him instead. Solomon rushes to save Saya from James, but during the battle he is accidentally cut by Saya's sword coated in her blood. He proclaims his allegiance to Saya as her chevalier once more, then leaves. In an alley, he begins to crystallize and shatters as Amshel watches. It is unknown as to whether Saya ever learned of his death as no one is shown telling her.