There were many animes in which the main character had transformed. The following were some of the more popular examples:
1." Tokyo Ghoul ": The protagonist, Kimki Yan, became a ghoul after mutation and embarked on a terrifying journey.
2 Naruto: The protagonist Naruto Uzumaki experienced many transformations and battle scenes during his growth, such as the transformation from a primary school student to a ninja.
3 One Piece: The protagonist Luffy experienced many adventures and transformations before becoming One Piece, such as the transformation from an ordinary fisherman to a pirate.
4." Attack of the Giant ": The protagonist Alan experienced many transformations and battle scenes during his growth, such as the transformation from a teenager to a giant.
5 " Ghost Blade ": After becoming a ghost, the protagonist Tanjiro experienced many battles and transformations, such as fighting ghosts and gradually adapting to the life of a ghost.
You might consider 'Gone Girl' where the main character's actions and motives are often morally ambiguous and at times outright evil. The plot keeps you on the edge as you uncover the layers of her character.
There were animes with big bosses as the main characters, such as One Piece, Naruto, Death Note, Slam Dunk, and so on. In these works, the protagonist usually had powerful strength and was a powerful villain at the beginning of the story, eventually growing into a powerful big Boss. The growth of these characters was also an important part of the whole story. It allowed the readers to feel the growth and changes of the main characters, and at the same time, it also brought more suspense and surprises to the story.
Yun Che was the male lead in the fantasy novel " Defiant Evil God ". He was the Demon Lord of the Northern Region and Emperor Yun of the Divine Realm. Yun Che had extraordinary medical skills and cultivation talent, and his comprehension was extremely high. He had a strong and determined personality, and he had been through many obstacles, but he was unyielding. He had continued to advance in the face of life and death. Yun Che had experienced many fortuitous encounters and was suspected to be blessed with great luck. Other than Yun Che, there were many female leads in the novel, such as Jasmine, Xia Qingyue, Xiao Lingxi, Cang Yue, and so on. Jasmine was Yun Che's teacher. Yun Che's early days had all been together with Jasmine, and the two of them had spent the longest time together. Xia Qingyue was Yun Che's wife. She was an Artifact of Fate created by the Primogenitor God to save Yun Che. She possessed a world-toppling beauty and peerless grace. Xiao Lingxi was Yun Che's aunt, and the two were childhood sweethearts. Cang Yue was the princess of the Gray Wind Empire and later became the empress. These characters played an important role in the novel.
There was no anime where everyone could become the main character. The storyline and character settings in anime usually had certain restrictions and characteristics. Not all anime characters could become the main character.
Some characters in anime might attract attention because of their special talents, skills, or background stories. For example, Naruto Uzumaki in Naruto, Monchi D. Luffy in One Piece, and so on.
In some anime storylines, the protagonist might need to experience a certain amount of growth and trials before finally becoming a hero or leader. For example, Alan Yaeger in Attack of the Giants, Azureshika Yuusuke in Death, and so on.
Although some characters in anime could become the main character, everyone's life experience and personality characteristics were different. Not all anime characters could be as charming and story-telling as the main character.
The main characters in web novels were usually not demon kings, but there were some novels or anime where the main characters were demon kings or similar characters. For example, Wei WuXian in "Grandmaster of the Devil" was a demon king level character, and Naruto in "Naruto" was also a demon king level character. However, the demon king's characters in anime and novels usually had a certain sense of mystery and great power, and were often related to evil forces.
There were many anime works about the main character being the Demon King, such as " The Demonic Patriarch,"" Naruto,"" The Sword God Realm,"" About My Reincarnation as a Slime,"" The Rebel Lelouch," and so on. The protagonists of these works were once powerful demon kings or leaders, but after facing certain difficulties or challenges, they gradually transformed into heroes or saviors to lead everyone to victory.
There were many novels that told the story of the protagonist transmigrating to the anime world. Among them, the more famous ones were " Full-time Expert,"" Douluo Continent,"" Battle Through the Sky," and so on. The protagonists of these novels displayed different skills and personalities in the anime world, experienced various adventures and challenges, and also launched exciting duels with other characters.
I think the most suitable novel for you is "Inuyasha: I'm the villain". The protagonist wakes up and travels back to the anime world. He finds himself back in time 300 years ago, with many familiar characters like Cuizi around him. The protagonist had to find the reason for his transmigration and start a new story in this world. I hope you like this fairy's recommendation. Muah ~😗