Bloodlust has a few — especially the ending — but the most notable arguably happens during D's negotiations for a new horse in a small town. The town sheriff and his posse — prodded into action by Leila — try to throw D out of town. The old man who owns the stables, however, dresses the sheriff down and explains why he's selling a horse to D: years earlier, D saved a group of children kidnapped by vampires from the same town, but was run out of town by the very people who hired him to do the job. When the sheriff still refuses to back down, the old man produces produces a BFG and points it at the group so D can ride out of town safely. Just after D thanks the old man for the horse (and presumably the safe passage), the old man returns the gratitude:
No, it's only fitting I thank you. It's the least I can do. I may be just an old fool now, stranger, but I can never forget a face like yours — and I'll never forget what you'd done for me back then.
The second novel, Raiser of Gales, ends with D leaving the town of Tepes after a (kind of) successful job. Lina, a genetically-modified vampire/human hybrid, delivers a stirring speech about the history of the Nobility and expresses hope that maybe, someday, humanity and the Nobility could put aside their differences to make both races stronger. She then dissolves, as she was an imperfect trial. As D leaves Tepes, the boy in love with Lina says he'll be going to the Capital in Lina's place to carry on her studies about the Nobility. D smiles.
doubles as a Brick Joke, at the beginning Lina says that when D departs from the town, he'll smile.
In the first movie, after Doris is revealed to be infected to her village, D comforts her brother Dan who struggles to cope with the news. D's insistence that his smile and encouragement will give Doris the strength they both need to endure their crisis helps to inspire Dan, who takes his words to heart and thus proves to be a valuable ally in resisting Magnus Lee's efforts to capture Doris.
Doris' love for D, and her fearing for his life prompts her to embrace him tearfully, full aware that D is half-vampire and thus tempted by his own vampiric urges. Luckily however, D regains his self-control and keeps her at bay, honoring his vow never to let his vampiric instincts bring others to harm.
During the ending of the first movie, when Doris and her brother are calling goodbye to D from the clifftop, D stops, looks up, and very subtly you can see his cheeks rise and his eyes narrow before he nods to them.