Keyaru

Keyaru or Keyaruga, is the main protagonist of Kaifuku Jutsushi no Yarinaoshi series. When transformed into a girl, he is referred to as Keyara.

After years of torture at the hands of his own allies, he manages to break free and manages to get the Philosopher's Stone. An item that guarantees every desire and goes back in two years time to start his revenge against the people who tortured him.

Appearance
Keyaru is a young boy of medium height with brown hair and red eyes, initially he is dressed in simple clothes he used in the village, then after the start of his revenge he uses a set of armor he stole from the Captain of the Guards. When he uses Heal's skill, his eyes turn green.

Pre-betrayal
Before the betrayal, Ketayru was a simple boy, rather innocent and with dreams, after realizing that he was a hero he was excited to save the world, and although he was very different for his class he was still happy.

Post-betrayal
After realizing that Keyaru's power is not normal, he is imprisoned and after being tortured, drugged, raped, his personality changes completely. In fact, because of the betrayal of the naive personality that he was, he changes to become more vindictive, sadistic, manipulative, cunning, evil, distrusful and full of hate.

Powers & Abilities
Heal:  By healing things and concepts, Keyaru performs various abilities from the Healer Class: Eye of Truth:  Also called as "The Eye That Sees Through Everything", is a powerful magic that Keyaru obtained by making a pact with the spirit of the stars. It allows him to get full information about the target's stats, such as: Magical defense, Physical defense, Level, Mana, Health, Class, Abilities, Passives, and Speed.
 * Recover: By manipulating time and matter, Keyaru return things to their original states, healing deep injuries from himself or others, nearly instantly. Using it to heal someone will cause him great pain, but later on the series he learns how to use this skill without getting any struggle at all.
 * Simulation: Every time Keyaru heals someone, he gains the fighting skills and experience from that person. He already used this skill many times before, retaining all the knowledge from different fighters, soldiers and mages.
 * Corruption: Destroys the target from inside, corrupting them. Keyaru usually refers to this ability as a One-Hit KO skill, though the full details are still unknown.
 * Steal: Can absorb all the mana from someone, or just a portion if he wants. If the target is a mage or fully dependant on mana, that person gets incapacitated and weakened.
 * Upgrade: Ability that allows Keyaru to modify things by "upgrading" them to a desired state.
 * Superhuman Augmentation: By upgrading himself, he can enhance his own stats (and also decrease them), such as strength, speed, magical defense, physical defense, and magical attack.
 * Transmutation: Keyaru can modify someone's body by transmutating them, allowing him to change their appeareance, physical stats, gender, and mind.
 * Memory Erase: While touching someone's head, Keyaru can mess up with people memories and can also erase them at will.
 * Shapeshift: By using Upgrade on himself, Keyaru can change his appearence.
 * Rewrite: Keyaru can use Upgrade on enchanted/magical objects, changing their functions.

Relationships
Anna: She was the most important person to Keyaru, the woman he loved and his first love, and in his own mind the only person who manages to keep a part of his sanity. After being raped all night by the Captain of the Guards, thinking it was Keyaru, she commits suicide. This event makes up for Keyaru's hatred and suffering, wanting to take even more atrocious revenge.

Keyaruga's Party
Freya: She was the one to invite Keyaru in her party. When she found out that Keyaru was just a healer and how he could even recover lost limbs, she drugged him and used him as a tool, sometimes for her own sadistic means. She was also the one who triggered the change in Keyaru's personality and was the first target of Keyaru's revenge. After acquiring enough strength to take revenge on her, he rapes her, erases her memory, slightly modifies her appearance to transform her into an ideal girl, while leaving her knowledge intact. He then turns her into his slave, often referring to her as his 'toy'.

After making her join him on his adventure, he convinces her that they are lovers, which she easily believes. During their adventure, they frequently engage in sexual intercourse. After Setsuna joins their party, Freya often gets jealous when he acts affectionate towards her. She now cares deeply about him and follows his every command.

Setsuna: She was a demi-human slave. After making his 'great escape', Keyaru buys her with the gold he acquired by selling the antidote to the citizens of Ranalita. She acted reluctant towards him and talked about her vengeance towards the people who burnt her village. However she quickly develops a bond with him after engaging in sexual intercourse with him in order to increase her level cap. She is also referred to as a 'toy' by Keyaru and has developed a romantic relationship with him, similar to Freya.

Kureha Clyret: She seems to develop a crush on Keyaru after he regenerates her lost arm. After his escape, they meet again as enemies, but after solving the "misunderstanding" she becomes attracted to him, both romantically and sexually.

Eve Reese: She is the Demon Queen Keyaru meets at the first world. After defeating her with the power he claimed by healing the heroes, she says that she has something she has to protect and vanishes.

After the escape he meets her in a tavern in Buranikka. At that time, she wasn't made demon king yet. He rescues her from a group of attackers and swears to protect her and make her the next demon king, in order to make co-existence between humans and demons.

Heroes
Blade: She is one of the Heroes, and one of Keyaru's main targets of revenge. She is homosexual, and has an obsessive love for Freya, in the previous timeline, when Freya drugged Keyaru and used him as a sex toy, she beat him until he fainted.

Brett: He is one of the  Heroes and and one of Keyaru's main targets of revenge. He is homosexual and has an obsession with Keyaru. In the previous timeline, he often raped him and called it a proof of his "love".

Norn: One of the heroes, and Freya's younger sister, according to Keyaru, she has the most evil and cruel nature and because of her skill in her schemes, she is the only one capable of killing him.

Etymology
His name and fake names Keyaru (ケヤル), Keyaruga (ケヤルガ), and Keyara (ケヤラ), alluded to the healing magics Kearu (ケアル), Kearuga (ケアルガ), and Kearura (ケアルラ) from the Final Fantasy series.