Keyaru

Keyaru (ケヤル), also known as Keyaruga (ケヤルガ), is the main protagonist of Kaifuku Jutsushi no Yarinaoshi series.

After years of torture at the hands of his own allies, he manages to break free and get the Philosopher's Stone. He then uses the item to go back four years time to exact 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 his Heal skill, his eyes turn green.

Pre-betrayal
While little of who Keyaru was before the betrayal is shown, he used to be a kind and simple boy with dreams. After realizing that he was a hero he was excited to save the world, and although he was very different due to his class he was still happy and didn't realize Freya's true intentions for him until it was too late.

Post-betrayal
After being imprisoned, tortured, drugged and raped, his personality changes completely to that of a vindictive and sadistic individual. Because his naive personality allowed him to be taken advantage of, he changes to become a manipulative and cunning misanthrope full of hate towards those who abused him.

Revenge is Keyaru's primary concern, although at least once he has mentioned the possibility of "living happily" once he has taken vengeance on his abusers. When asked why he seeks revenge, he says that the idea of people he hates being allowed to peacefully exist without consequences is disgusting to him. Contrarily to someone like Setsuna, he thoroughly takes pleasure upon taking vengeance, as seen by his happy laughter after having raped Freya and erasing her memories. The exception to this is the Knight Captain of Jhoiral's Guard, as even after the elaborate torture Keyaru devises for him, he shows absolutely no happiness nor satisfaction during it nor afterwards, presumably because the Knight Captain's actions resulted in the death of many of Keyaru's loved ones.

One of Keyaru's redeeming factors is that he has no desire to harm those who have done him no harm, and in fact makes it a personal rule not to drag them into his revenge; this applies even to people who are otherwise cruel like Princess Norn (until he discovers that she had a hand in executing the captured members of his village). Keyaru also has some sympathy for people who strive for justified revenge the same way he does, and will do his best to help grant them their desire with the condition that they also help him with his.

His relationship with the members of his party is hard to read. On the one hand, he commonly refers to them as his "toys" or "playthings" in his inner thoughts, implying that he has no real love for them and only sees them as tools. However, aside from some relatively very minor things (such as having Freia carry his luggage in revenge for formerly serving as the pack mule), he normally treats them only with kindness, completely at odds with his own treatment at the hands of Freya's party, and gets very agitated when one of them is harmed. Whether this means that he is more protective about them than one might think or simply possessive is unclear.

Plot
As he was one of the chosen heroes, Freya Arlgrande Jioral took Keyaru to Jioral Kingdom, where he identified himself as the Healing Hero. Unfortunately for Keyaru, prejudice against the healer class resulted in Freya, the Heroes and Jioral Kingdom abusing and torturing Keyaru to the point where he was addicted to a healing drug Freya fed him to keep him in line. Developing an immense hatred toward them, he eventually develops a resistance to the drug and is able to maintain his sanity. When the heroes are incapacitated by the current Demon King, Keyaru is able to defeat him with ease and reveal him to be a silver-haired woman. Using the Philosopher's Stone he obtained from her, Keyaru declares vengeance on Freya before reversing time by four years.

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. Initially, using it to heal someone would cause him great pain, but later on the series he learns how to use this skill without showing any signs of pain at all. It is possible that he has simply learned to ignore the pain the spell causes, as it is no longer significant to him compared to the agony he suffered on a daily basis while being the slave of the Hero Party.
 * 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 either absorb or copy some of the levels of a person, allowing Keyaru to level up. The same ability can also be used to absorb all the mana from someone, or just a portion if he wants. If the target is a mage or fully dependent 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 change his stat spread by enhancing some stats (such as strength, speed, magical defense, physical defense, and magical attack) at the cost of reducing others. He cannot, however, change his stat total.
 * Transmutation: By transmutating an individual, this allows him to change their appearance, physical stats, gender, and mind.
 * Memory Erase: While touching someone's head, Keyaru can change the memories of an individual and can also erase them at will.
 * Shapeshift: By using Upgrade on himself, Keyaru can change his appearance.
 * Rewrite: Keyaru can use Upgrade on enchanted/magical objects, changing their functions.

Alchemy:  Keyaru is a skilled alchemist. He is able to magically "transmute" matter into other forms, as seen for example when he turns a lead pipe into a key. He is also a capable creator of airborne poisons, such as an aphrodisiac that makes the target too sexually excited to fight, or a deadly paralytic agent. He keeps them in flasks that he shatters against the ground when needed, letting the deadly vapors spread. He also has needles to inject the poisons directly into a target for added effect.

Toxin Resistance:  Thanks to having trained his body extensively by consuming massive amounts of toxic mushrooms and having subsequently shaken off the effect of Freya's drug, Keyaru is immune or incredibly resistant to the effect of most poisons and drugs. This is what allows him to use his alchemical grenades to great effect, as the fumes that are debilitating to others have absolutely no effect on Keyaru.

 Intelligence:  Keyaru is extremely intelligent and cunning. He is shown to have an impressive knowledge of magical theory, being able to develop many unconventional uses for his own Heal spell, teach Freia how to best use her magic to her advantage, and rig an enchantment to his own benefit. He is skilled at developing strategies and tactics to ensure that any battle he partakes in swings to his advantage as much as possible. This is best illustrated during his assault on the Arena, wherein he not only infiltrates the place several weeks in advance to stealthily tamper with its defenses, but also develops a plan to swing the hearts of Jhoiral Kingdom's residents in favor of his cause. Keyaru is manipulative and knows exactly which buttons to press to turn a person into a loyal follower, as shown with Setsuna and Eve Reese.

Relationships
Anna: Keyaru treasured Anna as his first love, and regarded her the only person who manages to keep a part of his sanity. After Anna is raped by the Captain of the Guards, she commits suicide thinking he was Keyaru. When Keyaru learns of this event, he transmutes the captain into a woman, and has all of his men rape the captain.

Keyaruga's Party
Freya: When Freya 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 and slightly modifies her appearance to transform her into an ideal girl, while leaving her knowledge intact. He then turns her into his slave, and repeatedly refers 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 adventures, 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: After escaping imprisonment, Keyaru buys her with the gold he acquired by selling the antidote to the citizens of Ranalita. She is initially hesitant to cooperate with him, but quickly develops a bond with Keyaru after engaging in sexual intercourse 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 travelling back two years, he meets her in a tavern in Buranikka, though 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 create a 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 out of jealousy.

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 cruel, and because of her skill in her schemes, she is the only one capable of killing him.