There are many people in anime who are almost impossible to kill, with some of them being outright impossible to kill. These immortals typically come with great strength and power, sometimes using their incredible strength to overcome their enemies and surviving any attack that may come their way.
Some immortals prove to be more powerful than others. While some immortals use their long lives to benefit those around them, other immortals take advantage of their inability to die and use their power and long lives to try and take over the world.
10 Hiro Longs To Become Strong Enough To Protect Hime (Princess Resurrection)
Hiro Hiyorimi is the main protagonist of Princess Resurrection. When searching for his sister, Hiro was caught up in a horrible accident and died. After being resurrected by Hime, he becomes bonded to Hime and has to protect her as her blood servant. Hiro begins as being relatively weak but makes a vow to become stronger. He hopes to never die again and trains to become strong enough to protect Hime.
9 Ryuk Possesses The Ability Of Flight (Death Note)
Ryuk is the main shinigami depicted in Death Note. His job is to write the names of dying humans in his notebook. In return for performing his job, he gets to experience a prolonged life. However, Ryuk grows bored easily and sometimes gives his notebook to humans in order to entertain himself.
Ryuk has the powers of most other shinigami and is mostly invisible to humans. The only humans that can see shinigami are humans that have touched a Death Note. Shinigami can walk through walls and can't be injured, with any wounds healing almost as immediately as they are inflicted.
8 Kei Nagai Is One Of The Strongest Ajin (Ajin)
Kei spent most of his life believing he was an ordinary human. After being run over by a truck, it was revealed that he was actually an Ajin. The Ajin are immortal and not considered human by others.
Kei has the powers of other Ajin, capable of paralyzing enemies with a scream and his ability to create extensions of himself. All Ajin are able to create Black Ghosts, a dark form that they can control. Kei can create more ghosts than any other Ajin. Unfortunately, he also lacks control.
7 Akihito's Incredible Healing Factor Has A Terrible Price (Beyond the Boundary)
Akihito Kanbara is the half-human protagonist of Beyond the Boundary. He can heal from almost any wound, though it comes at a price. If injured seriously enough, he completely losses control of himself and begins to behave more like a wounded animal than a person.
Akihito is half-youmu. While most youmu seem to be total monsters, Akihito isn't the only one with compassion for humans, managing to make a few, close friends. His friends try to prevent his youmu side from taking over completely. While his full strength is never really shown, he is known to be one of the most powerful youmu in all existence.
6 The Silver King Can Manipulate Gravity (K)
The Silver King is one of the many kings in the anime, K. He was born Adolf K. Weismann but has used a few other names. When he gets amnesia, he begins living as an ordinary student under the name Yashiro.
Over time, Yashiro begins to regain his memories as the Silver King and starts using his powers again. As the Silver King, he is immortal and possesses the ability to manipulate gravity. He also possesses enhanced intelligence. Like the other kings, he can share his powers with his followers.
5 Piccolo Will Never Die From Natural Causes (Dragon Ball)
Piccolo is a powerful Namekian from the Dragon Ball series. Piccolo's father, King Piccolo, made a wish on the dragon balls for eternal youth. Piccolo inherited his father's eternal youth. Despite his immortality, Piccolo can still die from an outside attack.
Piccolo has faced death a few times, like when he had to deal with Gohan in his Giant Ape form, but he can also regenerate certain injured body parts. Like many of the Dragon Team, Piccolo utilizes ki energy to fight.
4 Father Sacrificed A Lot Of People To Gain His Power (Fullmetal Alchemist)
Father is the main antagonist of Fullmetal Alchemist. He created the Homunculus that Al and Ed spend a lot of the series fighting against. Father started off as a simple dwarf in a glass, but his existence would forever change when he began working with the king of Xerxes.
He promised the king immortality but took the power for himself. As a philosopher's stone, Father could basically ignore the ordinary rules of alchemy. To ensure his life would never come to an end, he prepared to give himself god-like power.
3 Isshiki Was Willing To Do Anything To Prolong His Life (Boruto)
Isshiki Otsutsuki was a member of the Otsutsuki Clan appearing in Boruto. The Otsutsuki live incredibly long lives. Many seem to have an interest in prolonging their lives as long as possible, and Isshiki Otsutsuki spent years searching for the perfect vessel to prolong his life.
While he was able to survive thanks to Jigen, Jigen wasn't capable of carrying the full weight of Isshiki's power. Kawaki is currently in control of his body, but it's possible that Isshiki will gain full control over Kawaki's body someday.
2 Kaname Was A Pureblood Vampire (Vampire Knight)
Kaname was one of the main love interests in Vampire Knight. He was also a pureblood vampire who had survived for centuries. Pureblood vampires were almost impossible to kill. Kaname had nearly limitless power.
He has shown the ability to shape-shift, possesses telekinesis, and can erase memories. He also possesses a sword, an anti-vampire weapon, and the ability to heal himself from almost any wound, though he can't heal from a wound to the head or heart.
1 Sebastian Has To Serve Ciel Forever (Black Butler)
Sebastian is one of the main characters from Black Butler. He was from another realm and was summoned by Ciel after the death of Ciel's twin brother, entering into an agreement with Ciel. Now, Sebastian works as Ciel's butler while protecting Ciel from a variety of threats.
Despite looking like a human, Sebastian isn't capable of dying. Coming across as the perfect butler, he uses his powers to help perform the various tasks assigned to him. At first, Sebastian had planned on consuming Ciel's soul after Ciel's death. This was prevented, though, and he will continue being Ciel's butler for all eternity.