Olivier

Olivier (オリヴィエ) was Alpha's ancestor and one of the three heroes who defeated the demon Diabolos. In reality, however, she was a pawn of the Cult of Diablos, being a survivor of their experiments, tasked by them with defeating the demon for their own ends.

Appearance
Olivier is described as a beautiful, gallant, almost divine even, figure of a woman warrior. Her appearance looks like a mirror image of Alpha and Beatrix.

She carries some kind of magical talismans on her head on the sides of her cheeks that form the appearance of a kind of helmet, which these are always attached to on her head (it is not known at the moment what function they fulfill).

In the light novel and manga, she is described as wearing beautiful emerald green armor, wearing a beautiful skirt with a cape on her back with metallic boots and carrying a powerful sword made by the cult for her. While in the anime, she wears a white robe that covers almost her entire body to below her knees without any footwear with a prototype magic sword.

Personality
It's unknown what her real personality was but Alpha's, Beatrix's descendant, description of her implies that she has a sense of justice as she believed defeating Diabolos would save the world.

However after being sealed inside the Sanctuary for centuries, she had been reduced to an emotionless state, possibly forced to serve the Cult of Diabolos.

Synopsis
Centuries ago, originally Olivier was a normal elf until she was kidnapped by the Cult of Diablos, to perform an experiment with her and all the other children, boys and girls alike they had kidnapped and collected to implant Diabolos cells, in an attempt to create powerful soldiers to fight the Demon King Diabolos. The experiments resulted in almost failure, since most of the children ended up dying, and a small group of girls survived because they could not tolerate the blood of the demon in their veins.

But luckily for the Cult, 3 girls had survived which turned out to be an Elf, a Beastkin and a Human, Olivier was one of the other 2 individuals, the cult carried out more experiments to make them strong and powerful, creating weapons and equipment for them so that when they are adults and ready, they would go to fight the Demon King Diabolos.

Years later, Olivier already prepared along with the other two, which is the Beastkin hero Lili and Human Hero (Freya; WN Only) went to exterminate the demon Diabolos by order of the Cult, which resulted in their defeat and Olivier cut off the demon's left arm with her sword, then sealed it in the Holy Ground. Then, she was cursed by Diabolos so that her descendants would be possessed with rotten bodies, along with the descendants of the others two heroes.

However, the truth was, Olivier was one of few people who are compatible with Diablos's cell. She was tasked by the Order to gather more Diabolos cells. Then, Olivier is treated like a man, because the Cult twisted history globally, so that no one would know the truth of everything or investigate it.

In recent years, the Wandering Swordsman Venom managed to summon her via Trial of Goddess at Lindwurm but Olivier won the match.

Holy Ground Infiltration
During the infiltration of the Holy Ground, the group consists of Alpha, Delta and Epsilon manage to infiltrate the Sanctuary with the help of their lord Shadow, along with Beta (disguised as Natsume), Rose, Alexia, and Nelson who held him hostage. There, Alpha reveals the truth of everything as well as her relationship with Olivier, and how Olivier is treated as a real man, she is a woman and how the cult distorts history, and for more later Nelson reveals himself and tries to kill everyone but Delta and Alpha confront him without problem.

Then Olivier is summoned as a puppet with no will of his own but with great magical power by Nelson to eradicate the members of Shadow Garden, but they retreat before Olivier started fighting them, especially with Delta, who was in ecstasy for fighting, after having defeated more than a dozen of Nelson's magical copies.

Later, Olivier is ordered by Nelson to kill Cid who was there along with Aurora ghost. Cid manages to dodge her deadly strike, but then after receiving multiple wounds on his body. In the end, he receives a fatal wound from Olivier (fake), but Cid takes advantage and destroys her neck to later impale himself and get rid of multiple Olivier's copies, and at the end he destroys the entire Sanctuary together with Olivier (fake) and Nelson.

Powers & Abilities
Being one of the 3 that survived of the Cult of Diablos' experiments with the implanted cells of the Demon Diablos, it can be assumed that Olivier was considerably the most powerful individual in the Heroes group, making her the most lethal weapon of the Cult, since she was able to defeat the demon and seal it. Shadow himself noted that the projection of Olivier summoned by Nelson paled in comparison to the real deal.

Trivia

 * Until now, Olivier's lineage is the most numerous compared to the other 2 heroines, being ironic since, Olivier being an elf, like his race, he should not have so many offspring due to his long life.
 * It is speculated that the Cult of Diabolos forced her and ordered her to have more offspring with her own and with other races such as humans and the Race opposed to the elves, which would be the dark elves, to harvest more blood from the heroes, since they had the blood of the Demon Diabolos running in their veins.
 * Olivier's descendants were mostly discarded or discarded by the Cult of Diabolos immediately, as they contracted Demonic Possession at a very early age, they could not use them to draw their blood to speed up the revival of the Diabolos Demon. therefore they went for the descendants of the other 2 heroes, but they still keep an eye on the elves in case one appears without possession.
 * Until now during the "Goddess Trials" that all Three Heroes were being held inside the Sanctuary for many years and the other 2 heroes of the cult, which are Lili and (Freya; WN Only) have not been seen being summoned. The only one so far to be invoked was Olivier.
 * In the anime, immediately after Cid unleashed "I Am Atomic! All Range Attack!", Olivier's face formed a smile.