Lyudmil is a character that appears in Castlevania: Nocturne of Recollection.
According to the radio drama Castlevania: Nocturne of Recollection, Lyudmil was a servant to Adrian in the days shortly after his mother Lisa's death. Lyudmil's parents and many of his fellow villagers were healed by Alucard's mother Lisa. When Lisa was falsely convicted of witchcraft, he attempted to help her escape. He ultimately failed, Lisa was burned (or hung) as a witch, and Lyudmil was declared a traitor. He became very embittered towards the humans who had betrayed her kindness and sought out Lisa's son, Alucard. When he found him, he told him of his past and how he felt about it. Alucard told him that his mother would not wish for him to hate the humans, as she had told him. With no where else to go, he insisted upon staying by Alucard's side. He becomes Alucard's servant and lives with him at Dracula's Castle.
One day, Alucard and Lyudmil are talking in the castle garden about some of the white flowers that Lisa loved. He reminisces to Alucard about some of the aspects of life at his old village, such as a crown of flowers that they would make to hand out to girls. Alucard asks him if he would like to go back there someday, but he says that he would be executed as a traitor and that he should remain with Alucard.
The temptation to return to his village would prove to be too much though, and Lyudmil would return there. However, he would only find destruction there. It is not clear exactly what had transpired, but it is possible that as the beginning of Dracula's revenge against humanity for his wife Lisa's death, Dracula's incubus servant Magnus had arrived at this town with other minions and destroyed or dispersed all the residents there. He may have brought Lyudmil to the brink of death, but left him alive as temptation to Alucard. Lyudmil would wake up to find Alucard beside him, but did not know how he had gotten there or what had happened. Magnus then tempted Alucard with Lyudmil's blood, saying that he would not die if Alucard would only take it. Alucard resisted for a while, but in the end, it is likely that he had given in. Alucard and his Imp would then defeat Magnus (either now or later), but this incident may be what triggered a brief episode in Alucard's life where he actively sought out the blood of humans. Magnus would later show Maria visions of Alucard draining the blood of young maidens, perhaps during this time period, although it is not clear if this vision was true or not.
It is not clear if Alucard did actually turn Lyudmil into a vampire, and Magnus would later like him to believe that he did, but it is clear that he eventually became a vampire somehow. Lyudmil would become a demon who festered with hatred for humanity for what they had done to Lisa. It is not clear what he was doing for 350 years, but in the year 1798 (one year after Alucard had awoken from his 300 year slumber), likely due to the machinations of Magnus, he returned and began to suck the blood of maidens in the village that Alucard and Maria had settled in. This drew the attention of the vampire hunter Richter Belmont and separately the "self proclaimed" vampire hunters Cyril and Alexis, and they arrived in the village to investigate. He fought with Magnus against Alucard, Maria, Richter, Cyril and Alexis. He eventually came to his senses and turned on Magnus. Due to his wounds during the battle, he died in the presence of his friend Alucard.