Captain Kostaki alone of a group of cruel Carpathians shows reverence towards Genevieve after a scuffle in a bar started by his bloodthirsty comrades and ended by her intervention. Genevieve later notes in One Thousand Monsters that he was the first vampire in the new age to treat her with respect, and one of few.
"Lady Elder." said Kostaki, saluting her before turning to leave. "My respects."
Genevieve and Beauregard, by now lovers, share one towards the end of the novel, when Charles has been entrusted by the Diogenes Club with what was, by all means, a task that should have meant his death. For the first time since his wife's death, he professes it:
"Gené, I love you." "And I you, Charles. I you." "I you what?" "Love, Charles. I love you."
One Thousand Monsters
Captain Kostaki's visibly developing, quietly dignified love for Genevieve throughout the novel. Something which is already obvious to everyone else in the cast of characters, and wryly remarked upon by Princess Christina Light, who telepathically informs Genevieve of it. How far he is willing to go for her is evident, and it is his realization of his love for her that helps him break the mental control one of the villain's has over him and save the day near the end. Doubles as crowning moments of awesome.
'If Lady Genevieve were harmed, Kostaki would execute every last one of Majin's monstrous forms - no matter that it meant going to war with the Emperor of Japan.'
'(He saw her face - fair as her spirit. He remembered her strength, her gentleness, her refusal to back down, her grace and wit...)'
'His sword raised, he turned to the Master and saw red hair and deception. An inverted cross. The dream of glory was written across ice. The Seven were a phantasm - their image collapsed and ran, turned to water. The sun shone, melting the lies. Not the sun: Lady Genevieve.'
Genevieve's own observations of Kostaki as they work well together through the course of the novel. Although there is a combination of her love for Charles at play, chronological canon being what it is, and her self loathing of her vampiric nature making it difficult for her to love other Vampires, there is still something evident and unspoken between them that may be explored further in Daikaiju. She even compares him to Charles at one point in the novel, noting a similarity between them as 'stalwart adventurers'. Emphasized when Kostaki rescues her from her watery cell after she has been falsely imprisoned for murder, bringing her dry clothes, and at the end of the book when they are returning west from Yokai Town. In defiance of Christina's earlier armor piercing question of her over the Captain.