I'm not sure about a specific 'Harry is Alucard's mate' fanfic off the top of my head. But you could also check Archive of Our Own (AO3). They have a great tagging system. Just search for the relevant tags like 'Harry' and 'Alucard' and'mate' and you might find some really interesting stories. It could be that there are stories where they team up to fight against common enemies while also exploring their unique relationship.
Well, you can try looking on fanfiction.net. There are often a variety of fanfics in different genres related to this concept. Some might focus on their first meeting, how they interact in a magical or supernatural setting, and how their relationship develops over time.
Look to Chapter 281 for the clearest answer. It begins with In his dream, he found himself in a strange world., keeps building through The upper half was fire, the lower half sea., and lands on Are you okay?" Jiang Yan covered his wound, the pain causing him some....
If you want the clearest chapter reference, go to Chapter 261. Early on, The village chief's eyes nearly popped out after he heard the whole story.; later, the chapter leans on Their village had been harboring criminals involved in illegal wildlife....
If you want the clearest chapter reference, go to Chapter 260. Early on, Yan Dabiao, who deeply felt the sting of deception, flew into a rage and...; later, the chapter leans on Damn bitch, go to hell!" Jiang Li, who was dodging the encirclement of the....
Look to Chapter 228 for the clearest answer. It begins with Huo Ziyang had not stepped out of the house for a whole week., keeps building through This week, he had holed up in front of the computer every day, fiercely..., and lands on Why did you hit Ziyang?" Huo Xuan, one hand holding a phone and.
The best chapter pointer here is Chapter 243, "How Could It Be Her?!". It opens with Hahaha, the young master's face has gone white, but I got a scare just now... and closes on Perhaps feeling that the atmosphere had become unbearably tense, Director....
Chapter 229 is the strongest chapter-level answer because it starts from Huo Ziyang's face had already turned deathly pale. and follows through on Isn't it enough to teach a child a lesson when he makes a mistake?.
A practical answer is Chapter 223, because it turns the idea into a concrete scene. The chapter opens with So, for the first time, Jiang Yan, who had always styled himself as the..., adds pressure through He could simply have someone send a flurry of gifts and make some..., and ends on The damned.
A practical answer is Chapter 231, because it turns the idea into a concrete scene. The chapter opens with Huo Xuan felt a burst of secret delight in her heart., adds pressure through My apologies, my apologies." "Does the bigwig want his fortune told too?"..., and ends on A cool sports car was.
If you want the clearest chapter reference, go to Chapter 220. Early on, I know everyone has many questions, and I'm here to answer them one by...; later, the chapter leans on Actually, from the very beginning of the seed selection phase, we designed....