In the world of anime and manga, when a character's fate is limited only to the author's imagination, plenty of characters find themselves in situations much worse than simply dying.
There are many reasons why an author would employ this tactic. Sometimes, a villain is established to be immortal and the heroes have to get creative with dispatching them. Some works aimed at children might be sheepish about actually showing a death onscreen and decided to have a fate that isn't death per se but prevents them from going after the heroes. And some horror works simply relish in ensuring characters who escape death, hero or villain, don't get to live happily ever after on the off chance they get to live.
10 Ojamajo Doremi: Majo Tourbillion Was Forced To Watch Her Loved Ones Grow Old & Die
This Witch Queen fell in love with a human and married him and had a son named Anri. Unfortunately, George died a few years after their marriage in an accident. Being a witch, she did not age like a human, meaning she was forced to watch her beloved son grow old and die, seemingly abandoned by his own children. All the while, Tourbillion faced fear and hatred from the suspicious villagers.
Consumed by her pain, she creates a curse to prevent other witches from revealing themselves to humans and traps herself in a sleep-like state. An evil manifestation of her negative feelings later comes to life and serves as a villain of the series.
9 Inuyasha: Naraku Had To Be Wished Out Of Existence
Naraku proved to be a formidable villain. He could regenerate easily after an attack. For the most part, killing him seems nearly impossible, as he can somehow overcome any limit he supposedly has.
When Kagome gets the Shikon Jewel, she eventually uses it to wish his spirit out of existence, in addition to the Shikon Jewel and the evil spirit within it.
8 Sailor Moon: Queen Beryl Arranges A Special Fate For Jadeite
Jadeite was the first of the four generals Queen Beryl sent to collect energy from humans, but these plans kept getting thwarted by the Sailor Scouts. Queen Beryl eventually got tired of his constant failures and threatened a special punishment for him: "Eternal Sleep," trapping him in a block of ice for all eternity. In a final showdown with Sailor Moon, Mars, and Mercury, the Scouts take him down with a plane. He survives, but Queen Beryl makes good on her threat, freezing him once and for all, trapping him in darkness.
In the manga, however, he just gets burnt to a skeleton by Sailor Mars, with the Dark Kingdom keeping his remains in a glass coffin.
7 Sailor Moon: Mimete Gets Trapped In The Virtual World
Sailor Moon didn't need to work too hard to take down the Witches 5 since they mostly killed each other out of jealousy. Mimete, the second witch, was an especially interesting case. When she learned she was already going to be replaced by Tellu, Mimete took drastic measures to take down the Sailor Scouts, which included putting herself into a giant screen. Before she could attack, Tellu, however, appeared and pulled the plug, trapping her in the machine forever.
In the manga, she is eventually destroyed by the Outer Scouts, who manage to take her down twice, after she was revived after her first death.
6 Naruto: Hidan Is Just A Head In A Hole
Hidan has the power of immortality, being able to survive as just a head and even reattach to his body. He forms half of the Zombie Pair with Kakuzu, who can repair himself with magic threads.
During a face-off, Shikamaru blew him to bits with exploding tags and removed his head, making sure to bury it in a pit inside forest owned by his clan, who will ensure it will never be found. Supplementary material suggests he might eventually die of malnutrition. On the other hand, it's also been said he'll probably rot before his immortality runs out.
5 Yu Yu Hakusho: There's An Entire Plant Species Devoted To This
In this series, Toguro the Elder can't die, so Kurama had to come up with a special way to take him down. He implants a parasitic tree on him that drains the victim of the life energy until they die, in addition to giving them hallucinations.
Since Toguro can't die, so he is condemned to the eternal hallucination of fighting Kurama and failing to win. Hiei later uses a similar plant to get revenge on Mukuro's slave master; this time, the plant will keep the victim alive unless the brain is harmed.
4 Fullmetal Alchemist: Father Gets Dragged Into The Gates Of Truth
Father, known for being the creator and leader of the Homunculi, ultimately wants to absorb the Eye of God, but when he is unable to become its vessel, Truth appears and mocks him, saying he must not have believed in himself to steal powers from others.
Father is then dragged through the Gates of Truth, desperately pleading to know what he did wrong, as he is forcibly made part of the abyss, a fate Truth assures will be the despair he deserves.
3 Fairy Tail: Zeref Is Cursed To Have This Fate
In this series' universe, Ankhseram is an ancient deity known for a powerful curse that renders the victim immortal but kills everything around them. The reach of death is even proportional to how much the victim cares about those around them.
It's eventually revealed that Zeref endured such a curse thanks to trying to bring his dead brother back to life. It's eventually implied the only thing that can break the spell is being in the vicinity of someone with an even stronger, deadlier curse.
2 Franken Fran: One Client Turns Into A Living Tumor
In this horror series, Shidou Miyako was an elderly woman who really wanted to live forever, going so far as to murder scientists who failed to grant her wish, as well as stealing their research. She ultimately went to Fran for help and she actually managed to reverse the aging process well enough to restore Shidou to her youth.
She then steals Fran's research and plans to have her beheaded, underestimating the fact that Fran would easily survive that, and injects herself with Fran's concoction, despite being warned that Fran wanted to test its safety. In the end, she is transformed into a mass of cancer cells, effectively a living tumor, the only cells that can exist indefinitely. Fran even muses she could live forever.
1 Hell Girl: This Is The Point Of The Series
In the world of Hell Girl, people can use a website to wish someone to Hell at a price: eventually, they'll be damned, too. Of course, that's the ultimate horror: people either sacrifice their chance at salvation to damn someone who would have probably ended up in hell anyway or innocent people end up unfairly sent to hell and the only closure is that the person behind the wish will eventually get their comeuppance.
Arguably, Hell Girl herself, Ai Enma, doesn't even have it that easy: she was offered as a sacrifice for her village, only to return from the dead and get revenge by burning down the village. Sent to Hell, the Lord of Hell forced her to become Hell Girl on pain of her parents being damned. Ai eventually breaks the curse by saving Takuma, but she ends up Hell Girl all over again by the third season.