Ciel

Ciel (シエル) is a fictional character in the Mega Man Zero video game series. Although not a playable character, she is considered the female lead of the series, having important roles in most of her appearances.

Her name means "sky" in French. She is voiced by Rie Tanaka.

Character history
Ciel is a human and former Reploid researcher that worked for Neo Arcadia. When Mega Man X disappeared eight years before the events of Mega Man Zero begins, Ciel created Copy X to replace him. Amazingly, Ciel is supposed to be aged 14 during Mega Man Zero, which means she built Copy X at the age of 6, making her a child prodigy. According to the "Mega Man Zero Official Complete Works" source book, she is one of the genetically altered children born from Neo Arcadia experiments with DNA, which is what allowed her to attain such a high level of knowledge at such a young age. Additionally, one of her ancestors, another female scientist, was apparently directly responsible for the creation of the original Mother Elf, from which all other Cyber-elves were spawned.

However, when the Neo Arcadia government began oppressing and executing Reploids to solve their energy crisis, Ciel migrated with Reploid refugees to a ruined city when she was 9 years old. Knowing they were being falsely accused, she felt guilt and decided she could not stand by helplessly, and she soon became somewhat of a mother figure to many of the Reploid refugees, particularly a young girl she named Alouette. Times grew more desperate, though, and she eventually found her only hope to be uncovering a legendary hero that most people didn't even believe in anymore: the legendary Maverick Hunter Zero. She sought and eventually found him, though it took the sacrifice of one of her Cyber-elves, Passy, to wake him up.

Mega Man Zero
Zero, whose memory was blank possibly due to "hibernation sickness", helped Ciel escape and then helped her with several missions for the Resistance. He kept protecting her dutifully, until he finally brought down Copy X.

After the fall of Copy X, Ciel and her band of Resistance members left their ruined base and joined up with another opposition group. Since that time, she has set herself to work on discovering a new source of energy to bring about peace, and handed off the reigns of running the Resistance off to Elpizo. With Zero's return to the Resistance, she redoubled her efforts to bring about peace.

Mega Man Zero 2
During the time period covered in the second game of the Zero series, Ciel researched the possibility of using two Baby Elves as a source of energy. This system was not completed until some time between the second and third games, and was called the "Ciel System". Also, in a conversation with Alouette, Ciel was supposedly saddened when departing the first Resistance Base. Although the reason is never revealed, some speculate that it has something to do with Zero's disappearance after Copy X's defeat.

Ciel is reluctant to allow the new Resistance commander, Elpizo, commence "Operation Righteous Strike". Her fears came true when the operation turns out to be a disaster, with most of the Resistance troops involved having been killed, except for Elpizo. Having been driven mad by his defeat, Elpizo leaves the Resistance in search of the Dark Elf, and Ciel resumes command afterwards.

Mega Man Zero 3
By the beginning of the third game, Ciel had completed the self-titled Ciel System and had sent the ruling body of government of Neo Arcadia notes describing the new energy system. Shortly after this, the scientist Dr. Weil assumed control of Neo Arcadia and attempted to force her to give him the system. Zero once again protected her and the Resistance from the forces of Neo Arcadia. Though defeated, Weil still controlled Neo Arcadia. Ciel, seeing this, decided to split the Resistance Base into two, the other into a mobile unit, able to travel to wherever they were needed. Zero, Ciel, Cerveau, Faucon, Hirondelle, Rouge, and Alouette went on the mobile unit, while the others remained in the main base.

Mega Man Zero 4
As the fourth game began, Ciel, Zero, and the Resistance came across a human caravan fleeing Neo Arcadia. It is then explained that Dr. Weil controlled Neo Arcadia since Copy X's departure, and that they escaped because the once human nirvana had become dangerous thanks to Weil's rule. Even though the human refugees didn't appreciate their help, partially because of the Resistance's cooperation with Reploids, Ciel asked Zero to aid them anyway. Ciel helps Zero to stop Weil's new device, the Ragnarok, from destroying the new human encampment at Area Zero, which also happened to be where the Eurasia Colony fell at the end of Mega Man X5. After a lengthy battle with Weil on the Ragnarok itself, they manage to save the humans and free Neo Arcadia from the clutches of Dr. Weil.

With this, peace between humans and Reploids had finally been achieved after their hundreds of years of war. However, the price was heavy as Zero (supposedly) dies on Ragnarok when it breaks apart and burns to bits in the atmosphere. Despite Zero's habit of resurrecting, it is assumed by many that it's decidedly impossible for him to have survived this time. Also, there is no need for him to fight anymore, since Zero had finally achieved the ultimate peace that he and X had been fighting for ever since the beginning.

During the fourth game's credits, Ciel falls on her knees and cries from Zero's death as Ragnarok's pieces fell from the starlit sky. At the credits' end, she stands up strong and dries her tears, promising to the missing Zero that she would not let his action be in vain, and that she would keep the eternal peace between humans and Reploids that Zero had finally been able to create. She then finalizes by saying that she knows Zero is still alive somewhere, and that she knows he will come back because she believes in him.

The fourth game's final scene shows Zero's broken helmet, lying on the broken ground where Ragnarok's pieces fell - with Zero nowhere obvious in sight. There is a silhouette slightly to the left of the sun that may or may not be a helmetless Zero.

Mega Man Zero: Complete Works Bio
"To me, you are Zero."

A human girl, formerly a Reploid researcher and scientist at Neo Arcadia. Though responsible for creating Copy-X after X's disappearance, she cannot help but feel that the persecution of Reploids is wrong and decides to leave Neo Arcadia. Since then she has organized the Resistance and successfully developed a new source of energy, the "Ciel System."

Mega Man ZX
In Mega Man ZX, it is revealed through recovered Data Disks that Ciel went missing shortly after discovering Model W and creating the six Biometals in response. Ciel is also revealed as the 'Sis' of Prairie, the commander of the Guardians, though they are not biological sisters. It is strongly hinted that Prairie is actually Allouette, due to this relationship with Ciel being identical to Alloutte's, as well as general similarities between Prairie and Allouette's character designs. In particular, they carry the same stuffed animal.

Manga
Different from her personality from the games, in the Rockman Zero manga Ciel is unpredictable and can be very aggressive, but she still cares for the others. She first appears being mentioned in chapter 2 by a Reploid, and first meets Zero in chapter 4 helping him to escape from Pantheons. Later, they are attacked by Leviathan, and Zero's weapons didn't work on her ice dragon. Ciel gave Zero a fire sword that helped him defeat the dragon, and Leviathan escapes. After this, Ciel takes Zero to the Resistance, where they are attacked by Fefnir. Ciel feels sad for his friends that died in the battle, specially when Passy supposedly died when used her power to recover Zero from his wounds. After they escape the base, Rockman Zero and Ciel takes different directions, as he doesn't wanted to join the Resistance. After Neo Arcadia is defeated, she appears shortly talking with her older sister, Cial, the ruler of Neo Arcadia. Copy X only appears in the manga as an unnamed fusion of the four guardians.

Trivia

 * Ciel is one of the few human main characters in the main Mega Man timeline; like most of them, she is also a scientist.
 * Throughout the dialogue in the series, Ciel is strongly hinted to have feelings for Zero, regardless of the fact that he's an android. Some fans also believe that Zero even reciprocates these feelings.
 * Ciel's Japanese voice actress, Rie Tanaka, also did the voice of Lacus Clyne, one of the two female leads of the anime Gundam Seed.