In the Middle Ages, Vlad the Impaler (Luke Evans), the prince of Transylvania, finds himself plagued by a dark past. As a young boy, he was taken captive by the Turkish Empire and trained as a soldier in the Sultan's elite Janissary corps, where he earned the notorious title of the Impaler due to his brutal skills, accumulating a staggering number of kills. However, after becoming disillusioned with his violent ways, Vlad abandons his past and returns to rule his homeland in peace.
One fateful day, while in the forest with his soldiers, Vlad stumbles upon a Turkish helmet in a stream, igniting fears of an impending invasion by the Turks. Following the stream, they discover a gruesome high mountain cave, littered with bones. There, they are attacked by a terrifying creature lurking in the shadows. Vlad manages to escape back into the light, leaving his men to their fate. Upon returning to his castle, he learns from a local monk that the creature he encountered is a vampire—a former man who had made a pact with a demon for supernatural abilities.
The plot thickens when Vlad is celebrating Easter with his beloved wife Mirena (Sarah Gadon), their son Ingeras (Art Parkinson), and their subjects, when a Turkish contingent arrives. Sultan Mehmed (Dominic Cooper) demands a massive tribute of additional boys for his Janissaries, threatening Vlad's sovereignty. As the situation escalates, Vlad, realizing the futility of his situation, offers himself as a substitute for the boys, but the Sultan cruelly insists on taking Ingeras as well.
Desperate to protect his family, Vlad revisits the vampire's cave and strikes a precarious deal: he will drink the vampire's blood, gaining temporary vampire powers, but must resist the overwhelming urge to drink blood himself for three days to regain his humanity. After accepting this dark offer, he wakes up in the forest, transformed with heightened senses, extraordinary strength, and the ability to morph into a swarm of bats—yet he is now vulnerable to the sun, which burns his skin.
Back at Castle Dracula, as the Turkish army launches an assault, Vlad single-handedly annihilates the invaders. He sends his people to Cozia Monastery, perched on a mountain edge, in hopes of safety. However, during the journey, Mirena learns of Vlad's curse but clings to the hope that he can reclaim his mortality once the Turks have been vanquished. A gypsy named Shkelgim, who understands Vlad’s new nature, offers his blood, but Vlad declines.
As they reach the monastery, the Transylvanian forces are ambushed by Turkish soldiers. Despite repelling the attackers, Vlad’s newfound strength raises suspicions among his subjects. When a monk discovers the truth about Vlad's transformation, he incites the villagers to imprison Vlad in a burning structure. However, the smoke blocks the sunlight, granting him an opportunity to escape. In a fit of rage, he reveals his dark transformation was solely to safeguard his people from the Turkish threat.
That night, the Turkish army surrounds the monastery, prompting Vlad to summon an immense swarm of bats to fend them off. Yet, this is merely a diversion; a smaller group of Turks infiltrates the monastery, taking Ingeras hostage. In a tragic turn, Mirena falls from the monastery wall while trying to rescue their son, and in her final moments, she implores Vlad to drink her blood, hoping to empower him to save their child. Reluctantly, he complies, thus completing his transformation into a full-fledged vampire.
With his new capabilities, Vlad returns to confront the Turkish army and kills many soldiers, converting some of them into vampires as well. Meanwhile, Sultan Mehmed, aware of vampires’ weakness to silver, prepares an ambush using silver-lined traps. The unlikely battle leads to a fierce showdown between Vlad and Mehmed; eventually, Vlad skillfully evades his foe and plunges the Sultan into chaos, claiming the title of "Dracula, Son of the Devil" and draining Mehmed’s blood.
Emerging from the shadows, he faces a tremendous dilemma when confronted by the other vampires who demand his son’s life, refusing to accept Ingeras as a human. Seizing the opportunity, the monk returns, wielding a Christian cross to hold back the vampire faction. Dracula, with a heart full of sacrifice, sends Ingeras away and uses his powers to create a barrier against the sunlight, incinerating his fellow vampires in a blaze and leaving behind only the ashes of his once-human self.
With Europe spared from devastation, Ingeras is crowned the new Prince of Transylvania, believed to be Vlad the Impaler's legacy. Yet, the legend is not over; Shkelgim secretly revives Dracula using his blood, highlighting that the darkness never truly fades.
In present day, Vlad encounters a woman named Mina, who bears a striking resemblance to Mirena. Their conversation reveals a shared poetry line, setting the stage for the return of Dracula. Observing from a distance, the vampire who cursed him prepares for future games, ominously declaring, > "Let the games begin."
