Dark Elf (Mega Man Zero)

History
Before the events of the video game Mega Man Zero, The Mother Elf was created as the ultimate weapon during the era of Cyber Elf development, towards the end of the Maverick Wars, a fictional world wide battle that occurred in the Mega Man X series. As revealed in Rockman Zero Official Complete Works, she was created from the Maverick Virus data in Zero's body, as a "Sigma Antibody Program" capable of counteracting the Maverick Virus and Sigma's DNA. This was not the first attempt made to counteract the threat of the Virus; however it was the first of such attempts to actually be successful on a large scale. According to legend, Mega Man X used the power of this Elf to finally destroy the Maverick Virus' negative attributes for good, thus ending the Maverick Wars. The fighting did not cease, however.

Following the construction of Neo Arcadia, the Elf was stolen from a laboratory by the evil Dr. Weil, who reportedly placed a "curse" on her. Dr. Weil then used her to instigate the Elf Wars. As revealed in Mega Man Zero 3, this period was so violent that 90% of all Reploids and 60% of all humans were killed. X and Zero together stopped Weil and his reploid Omega, and after Zero went to sleep for 100 years, X sealed the Elf away at the base of Yggdrasil for good using his own body as the seal.

The Elf then disappeared into myth and legend along with Zero for 100 years, until the commander of the Resistance, Elpizo, sought to gain the power of the Elf during the events of Mega Man Zero 2. This quest led Elpizo to seek out two Baby Elves, which in turn led him to an area deep inside Neo Arcadia, where he destroyed the original X's body and released the Dark Elf. The Elf gave Elpizo powers, but not enough with which to defeat Zero. After healing Elpizo and turning him into a Cyber Elf, the Dark Elf vanished after faintly saying "... Zero...".

The Dark Elf was seen again in various forms of prominence during Mega Man Zero 3, mostly tying into the mysterious Dr. Weil. It was Neo Arcadia's goal to recapture the Dark Elf, and Dr. Weil, an exile from 100 years prior, returned with his creation Omega under false pretenses of helping Neo Arcadia capture the Elf, when all he really wanted was to use the powers of the Elf for his own purposes. Zero saw through the facade, and defeated Weil's reconstructed Copy X while hunting the Dark Elf. At the end of his journey, Zero encountered the Elf once more, in which it powered up his original body (inhabited by Omega). Upon Omega's ultimate defeat, the curse of Weil was finally broken, and the Dark Elf became good once again. She protected Zero from the explosion caused by Omega's destruction, and took him back to the Resistance Base. What happened to the Mother Elf afterwards is unknown.

Personality
The Dark Elf doesn't seem to have much of a personality other than the fact that it knows little more than destruction and death. She does, however, speak of Zero, and it almost seems that she is calling Zero to do something, perhaps to help her. At the end of Mega Man Zero 2, she turned good briefly to allow Elpizo to survive in the form of a Cyber Elf. This trait in itself shows the Dark Elf's true personality shining past her wretched curse. During Zero 3, more of this personality was shown as the curse was finally broken. It has been speculated that the Mother Elf could be based off of Iris from Mega Man X4; the fact that she turns Elpizo in to a Cyber Elf suggests that she may herself be a former Reploid, and Zero briefly mentions at the end of Megaman Zero 2 that he "feels that he knows her", implying he may have known her before she was a Cyber Elf. After being "saved" from death, Elpizo declares "she is not evil..." and, ironically and possibly symbolically, the Mother Elf changes into the Dark Elf against her will. This theory was very popular at one time, however it is dispeled by Rockman Zero Official Complete Works (released in 2006), which states that the Mother Elf was originally created from the Maverick Virus data in Zero's body (the reason why he feels that he knows her), and therefore she is not a former Reploid.