The user can kill vampires and vampiric beings, whatever it may be, and is able to handle the strongest, toughest, most dangerous of vampires and gain resistance to their powers. They can also be immune to becoming a vampire if they are bitten or otherwise attempted to be turned.
Felicia Book (American Vampire), senior director of the Vassals of the Morning Star, makes use of her enhanced sense of smell, reflexes, and strength as a half-American vampire, alongside wooden ammunition, in her fight against vampires.
Orphaned at a young age after witnessing his parent's brutal murder at the hands of vampires, Travis Kidd (American Vampire) would go on to become one of the greatest independent vampire hunters in the 20th century during the early 1950s...
...with ingenuity motivated by vengeance, he created Wooden Teeth as he likes to bite them back.
Rayne (BloodRayne series) makes use of her half-vampire heritage to hunt other vampires.
Belmont Clan (Castlevania series)
The Belmont Family (Castlevania) were once known for hunting monsters, especially vampires. Trevor Belmont, the last of his family, was the one who recently destroyed Dracula.
The Dawnguard (The Elder Scrolls V: Dawnguard) is a very proficient order dedicated to the eradication of vampires through sun-based magics and specialized equipment.
Auriel's Bow (The Elder Scrolls V: Dawnguard) is a divine weapon that uses the power of the sun to burn away the undead.
Dawnbreaker (The Elder Scrolls V: Skyrim) is the Daedric Artifact of Meridia, and has the power to "burn away corruption and false life".
Alexander Anderson (Hellsing)
The Barbed Cross (inFAMOUS: Festival of Blood) is a vampire-slaying weapon wielded by both Father Ignatius and Cole MacGrath.
Moebius the Time Streamer (Legacy of Kain) could cause serious harm to vampires with his personal staff.
Eric Brooks/Blade (Marvel Comics) excels in using his half-vampire state to fight vampires.
The Templars (Plague Inc.), a.k.a. Templar Industries, is a private military corporation that exists to fight vampires formed by the Shadow Plague.
Kresnik (Shin Megami Tensei) is a being that specializes in hunting Kudlak, a type of vampire.
Anthony (Ultimate Marvel) was once considered the world's greatest vampire hunter until he was turned into a vampire and gathered all the vampire clans under his control, becoming the undisputed King of the Vampires.
As the brother of Dracula, Michael Morbius (Ultimate Marvel) can not only fight vampires, but can even turn those who have not been completely converted to vampirism back into humans with his bite.
Peter Parker/Blood Spider (Ultimate Spider-Man) fights the denizens of the Vampire Universe regularly.
Vampire Slayer (Valkyrie Crusade)
Zero Kiryu (Vampire Knight) is an ex-human vampire, a vampire hunter, and wielder of the anti-vampire handgun Bloody Rose.
Grünfeld Bach (Vampire: The Masquerade – Bloodlines) is an elite vampire hunter and an Inquisitor of the Society of Leopold who can empower himself with True Faith to fight powerful Kindred.
After his mother was killed by them, Jefferson Twilight (The Venture Bros.) dedicated his life to hunting down and killing African American variant of vampires known as Blackulas.