Alucard is the most powerful and arguably the oldest vampire in the Hellsingverse. He's well over five centuries old and he's both the fictional Dracula from Bram Stoker's Dracula as well as the factual Wallachia ruler Vlad Dracula (a.k.a. Vlad the Impaler).
Alucard vs Cheddar Priest and Ghouls
Alucard vs Luke Valentine
Alucard vs Rio Swat Police
Alucard vs Tubalcain Alhambra
Alucard vs Rip Van Winkle and Millennium Vampires
Alucard vs Artificial Vampire Army and Papal Crusaders Army
Alucard vs Alexander Anderson
Alucard vs Walter Dornez
Powers and Abilities:
Alucard has a huge variety of abilities as a vampire:
Strength: As a well known standard for vampires, they possess monstrous strength capable of ripping apart human bodies with great ease. As the strongest vampire, Alucard can also rip right through other vampires. His physical strength enables him to easily wield the Jackal, which is something that humans cannot do. He is also able to slice through Tubalcain's magic card, which is hard enough to withstand the force of a depleted uranium shell being fired right at it and remain unscatched, and his arm.
Speed: Alucard is very fast. He can move at speeds that he appears as a beam of light identical to Luke Valentine and he can keep up with a vampirized Walter and blitzed Anderson augmented by the Nail of Helena and became a monster.
Reflexes: Alucard has an extraordinary reaction time. He was able to catch Rip Van Winkle's magic bullet, which was able to reach a Mach 3+ SR-71 Blackbird flying directly down at it in an instant and destroy missiles already released, in his mouth.
Durability: Alucard is extremely durable. He can take bullets from multiple high caliber rifles fired right at his chest, limbs, and face without ever being fazed, even when reduced to a puddle of blood. He's also able to take the damage that Tubalcain's cards dealt despite the fact that they slowed down his regeneration powers, the bullets fired from Luke's M1 Garand right at his skull, magic bullets despite the fact that they were able to kill several artifical vampires with just one shot, and being thrown into multiple buildings by Walter.
Levitation/Flight: Alucard can levitate himself high into the air. This also works when jumping, in which he massively increases how high and far he jumps and can slow down how fast he's descending to make his fall completely safe. He can also walk up vertical surfaces.
Third Eye: Alucard can form a third eye on his forebead just by imagining it. It allows him to extend his vision by several hundred meters, focus on images to attain superior accuracy and aim, and to destroy illusions and magic barriers.
Regeneration: Alucard's regeneration abilities is above any vampire and is probably only rivaled by Monster Anderson upon using the Nail of Helena and maybe the Captain. Alucard has regenerated from being blown to pieces by gunfire, reduced to a puddle of blood, decapicitation, being consumed by fire, burfication both vertically and horizontally, limbs, and damage to internal organs such as his heart and brain. He's also capable of regenerating a new body from bats that appear out of nowhere and ressurect himself.
Immortality: Alucard does not age and has an eternal lifespan, though this is limited to how much blood he consumes and the amount of souls he has. It's known that he's invulnerable to attacks that would have killed him, such as when multiple blessed bayonets pierced his heart, decapicitated him, and then pierced the head. Alucard lost one soul or "life" but was able to regenerate easily regardless.
Intangibility: Alucard can phase through solid objects.
Shapeshifting: Alucard can change his appearance and form at will. He can turn to animals, mist, a shadow-like substance, or into other human forms.
Telekinesis: Alucard can move objects using his mind, such as when he closed a door, lifted six adult-sized officers into the air and onto several flag poles, gathered smoke around him to form a dust cloud, and when he moved an inactive, half-destroyed aircraft carrier.
Other abilities include: Invisibility (anime/OVA only), Teleportation (anime/OVA only), hypnosis/mind control, control over a force of darkness, blood sucking, and immunity to most weaknesses vampires have.
At the end of the series, Alucard gains Schrodinger's soul as well as his powers. He can now control and manipulate physics at the quantum level. This allows him to distort reality and he also becomes omnipresent. He now exists everywhere and nowhere at the same time, making him truly immortal and gives him the ability to teleport anywhere he wants instantly just by a mere thought.