Hellsing is the tale of a secretive organization that works to wipe Cheddar village off of vampires. It is a classic vampire-themed anime, with Alucard and Seras Victoria as the two leads. While Alucard is a powerful vampire armed with a handgun, Seras Victoria takes over her father's organization 'Hellsing' to wipe off the vampires, who pose a threat to the world.
In the chaos that ensues, Seras Victoria gets mortally injured. Here's the catch: instead of letting the girl die, Hellsing gives her the option of staying alive as a vampire. It's not difficult to guess, Seras takes the option and starts her life as a member of Hellsing. Seras' character arc takes a new turn and so does Alucard's.
The central themes of Hellsing are gore, Horror, Vampire, and thriller. There are some other fantastic anime that belong to the same genres and are themed in a somewhat similar fashion. Below is the list.
10 DEVILMAN CRYBABY (JANUARY 2018)
Devilman Crybaby is the story of Akira Fudou, a gullible cry baby. Ryou, his best friend takes him to a Sabbath, on the pretext of researching the devil. All hell breaks loose when demons possess the partiers at the Sabbath. Unable to fend for himself or his friend, Akira joins with devil Amon and becomes the Devilman.
Now a crybaby at heart but a Devilman nonetheless, Akira and Ryou work together to save the humanity from the demons that stole his innocence in the first place.
9 DRIFTERS (OCTOBER 2016- DECEMBER 2016)
Drifters is the story of a rearguard Toyohisa Shimazu who is mortally wounded in the Battle of Sekigahara in 1600. Moments before his death, he's pulled into a hallway by a man named Murasaki. On the other side, Toyohisa learns of the political unrest caused by the Orte Empire.
Toyohisa is recruited into an organization called 'Drifters' who must fight the warring enemies called 'Ends'. It is a war of righteous Drifters against the Ends for freedom. Like Hellsing, Drifters is about an organization battling the wrongdoers, although vamps seem absent here.
8 TRIGUN (APRIL 1998- SEPTEMBER 1998)
What do you call a man who has a $60,000,000,000 bounty on his head? The Humanoid Typhoon. Meet Vash the lead of the anime, who's been an assassin for fun. He's exterminated human populations, those who looked him in the eye, let alone those who rebelled against him.
However, there's a lot of water under the bridge, since Vash now has turned into a donut loving goofball. He travels the Planet of Gunsmoke with two of his insurance agents. Trigun is about his struggle to not to break bad and to keep up with the moral life. For the similar character twists and developments, it feels closest to Hellsing.
7 CLAYMORE (APRIL 2007- SEPTEMBER 2007)
Claymore is quite similar to Hellsing, in that demon extermination, lies at the heart of both. Clare is the protector of Raki's Village, who seeks to battle it out with the flesh-eater demon, Youma. Clare is half-human and half-youma, known as Claymore. Whereas Youma is a shapeshifting demon, with a thirst for human flesh.
As the story progresses, we learn that Raki follows into Claymore's footsteps after he loses his family to the cannibal monster. With each town cleansed of demons, Clare and Youma are a step closer to facing off each other. Watch it to fall in love with the world of Demons and their anti-thesis.
6 BLADE (JULY 2011- SEPTEMBER 2011)
Blade traces the story of a man by the same name, who's a Daywalker- half-vampire blooded and half-human blooded. Blade was born with this abnormality because a vampire had attacked his mother in the past. This is a classic revenge story, wherein Blade, day in and out, works to hunt the vampire who attacked his mother.
As Blade is sent off to Japan for work, he finds the perfect opportunity to track down Deacon Frost, his mother's attacker. Tracking him, of course, isn't an easy task, so Blade takes the help of an organization 'Existence' in doing so.
5 BLACK LAGOON (APRIL 2006- JUNE 2006)
This may be probably the farthest from Hellsing in the list, in that there is no supernatural theme here. But there's enough gore and action to satiate your tastes like Hellsing. Black Lagoon talks about the life of an ordinary businessman, Rokurou Okajima. He breaks bad while on a business trip that doesn't go as planned.
Rokurou is captured by an organization of mercenaries called Black Lagoon and is forced into operation as fish bait. The operation goes downhill, but Rokurou breaks bad and decides to stay with Black Lagoon.
The underlying themes of Black Lagoon may not be so much about survival, as they are about morality, ethics and the philosophy of right and wrong.
4 BLOOD+ (OCTOBER 2005- SEPTEMBER 2006)
Blood+ as the name suggests, deals with a lot of gore, from the eyes of the lead, Otonashi Saya. Based on a similar post-apocalyptic theme, a young woman and her henchmen, kill defenseless commoners. You see the entire tale through the eyes of a girl named Saya. However, all of this is in retrospection.
Now a year after the war, Saya has forgotten the memories of the apocalypse. Until one night, she's attacked by a monster. As the classic horror trope would have it, Saya is saved out of blue by a man named Haji, who genes off the creature. However, in the coming moments that ensue, Haji forces her to drink his blood, citing it to be the only means of battling the monsters. And so she does.
Almost paralleling Hellsing, both Saya and Haji are set off on a mission to defeat these monsters. Oh wait, they are enrolled in an organization with a similar purpose, too.
3 TRINITY BLOOD (APRIL 2005- OCTOBER 2005)
Trinity Blood is set in a world destroyed by Armageddon. There's an ongoing fight between vampires and humans causing further destruction. The Vatican church as such is the only protector of humans, but it has to rely on its allies from time to time. The protagonist, Abel Nightroad is one of the priests from the Vatican committed to his duty. But there's a slight twist in the story, Abel is also a Crusnik, a vampire who feasts on the blood of other vampires.
Trinity Blood almost parallels with Hellsing. The protagonist is a vampire who encounters a young girl (Esther in this case). Together Abel and Esther venture out to navigate their own paths while stopping the evil forces.
2 DEVIL MAY CRY (JUNE 2007- SEPTEMBER 2007)
Devil May Cry is based on a video game by the same name. The anime tells the story of Dante, part human and human demon committed to ridding the society of the ills of demons. Dante owns and leads the organization 'Devil May Cry', through which he seeks to exterminate demons that are a nuisance to the society. Aided by two guns, Ebony and Ivory, Dante goes on his extermination missions.
The similarities with Hellsing are many: Dante yields a sword and Alucard, his gun. The genres of fantasy, demons, and gore, also parallel in both. Devil May Cry tells the story of a complex lead character, just as Hellsing does.
1 BLACK BUTLER (OCTOBER 2008- MARCH 2009)
Black Bulter is a dark tale of selling one's soul to seek revenge. The protagonist, a young boy named Ciel Phantomhive is "the Queen's Guard Dog". Ciel keeps stable Her Majesty's empire and is aided by his Bulter Sebastian Michaelis. But that's not all about the story. Ceil's past hides a secretive tale of revenge. As a young boy, Ciel loses everyone precious to him. So, he sells his soul to the devil in exchange for revenge. Ceil Phantomhive is thus a soulless boy, who owns 'Phantomhive Corp' to carry out his revenge plans.
The overarching theme of Demons, Supernatural parallels Hellsing. There's an added bonus here though, Black Butler is comical from time to time.