Alucard is the primary antagonist of the manga Rosario + Vampire. He is a Shinso vampire and the former ruler of a nation of monsters, and the founder of the anti-human organization Fairy Tale.
Alucard has thus far displayed traits more akin to an aimless beast of little or no intelligence, however he is noted for having two driving forces in his personality. Firstly, for a yet unknown reason, Alucard detests humanity, such that he became a monster and then tried to wipe them out 200 years ago. Secondly, due to his 200 year slumber and the sheer hunger he is suffering from because of it, Alucard is a voracious and self-indulgent eater who sees everything around him at the moment of awakening as mere food. This includes other monsters, his "supposed" allies, his own granddaughter, Akua, (although it is not clear as to whether he even knows who she is), and basically anything that breathes.
It is assumed that Alucard's mind is indeed still intact, hinting that he does have intelligence, in any event, his ravenous hunger and sheer cruelty still make him little beyond a monster.
In the fifteenth century, Alucard was the king of a small country of monsters in Wallachia who desired co-existence with humanity. However, the humans within the neighboring kingdoms feared Alucard's powers and wiped out his kingdom, leaving Alucard and a young vampire girl named Akasha Bloodriver as the only survivors. With Akasha as his only companion, Alucard traveled to the east, thirsting for revenge against humanity and longing to rebuild his fallen kingdom. Incorporating numerous monsters into his being through the use of his shinso abilities, Alucard became a powerful monster that threatened the world. To stop him from destroying humanity, the Three Dark Lords battled him, finally defeating him when Akasha allowed herself to be absorbed by him to seal him from the inside. Alucard's monster form was imprisoned beneath the Shuzen castle; before he was sealed away, however, Alucard created a clone of himself which assumed two identities; the Masked King, who created the anti-human organization Fairy Tale and the Miao family, and Miyabi Fujisaki, head of Fairy Tale's 1st Division.
Centuries later, Alucard's true form was awoken when Moka unleashed her Shinso powers against Aqua Shuzen when the latter attempted to kill Akasha. Alucard subsequently destroyed the Shuzen manor and attempted to feast upon Moka, but Akasha sacrificed herself to seal him away once more. Some time afterwards, Alucard was hidden away in the Floating Garden, the headquarters of Fairy Tale.
Years later, Alucard's clone, Miyabi Fujisaki, was assigned to marry Mizore Shirayuki of the Snow Village. When Kahlua, Gyokuro's daughter, was sent to wipe out the village, Miyabi arrived to stop the fight between her and Moka, as Kahlua was at risk of dying from her injuries.
Moka is later abducted by Fairy Tale and placed in a special seal next to Alucard, designed to shatter her Rosario seal and free Inner Moka, and thus awaken Alucard. Though she attempted to delay his revival, Inner Moka was eventually awakened at the sight of Aqua seemingly killing Mizore and Kurumu, allowing Alucard to awaken as well. Upon his revival, Alucard consumed many Fairy Tale monsters before seemingly being placed under Gyokuro's control through the use of her rosario. She then assimilated with Alucard to increase her power; however, after Moka took the rosario away from her, she was devoured by him.
It was then that the Masked King arrived and revealed himself both as Miyabi and Alucard's clone, explaining he had orchestrated the events to test how much power Moka's rosario had over him. Easily defeating the group, Miyabi prepared to kill Moka, but Aqua came to her rescue, severing his arm. It was revealed that Alucard had previously made a deal with Aqua, who desired revenge after humanity after they killed her friend Jasmine, that she would help free him in exchange for sparing Moka. Angered that he had gone back on their deal, Aqua attacked Miyabi, who crashes the Floating Garden into Tokyo before merging with his true body.
Wreaking havoc across Tokyo, Alucard is opposed by Moka, her friends, two of the Dark Lords, and the human military. Though Alucard proved to be near-unstoppable, he was eventually subdued when Tsukune attacked the rosario to Alucard's chest, recreating the body of Akasha, who comandeered his body. Alucard confessed that Akasha was what had given him meaning after his kingdom was destroyed, and willingly accepts defeat to join her in the afterlife. With help from the other Dark Lords, the pair enact a self-destruct spell, and the four of them vanish from the world.