|“||Do not forget, the Master is the only true human remaining. The System exists only to protect and serve the Master. We exist for this and only this purpose.||„|
|~ - Sera|
Sera is a very serious villain, and has a machine-like personality. She at first was very stoic, as she only focused on serving the system. She also did not understand why The Master trusted Mega Man.
Near the end of the game, though, she begins to be more emotional. She displayed emotions such as sadness, frustration, and jealously, which she initially view as bothersome.
Before Mega Man Legends 2
Sera was created to by the mother unit of the Elysium system, a task she was very devoted to. She also devoted herself in serving the Master, who was the last human remaining.
She was also in charge in a mission to activate the Carbon Reinitialization Program, which would replace all the carbon life with clones of the humans who created the system. To do so requires the four keys to the library, from Yuna, who is the mother unit of the Terra system.
Sera repeatedly warn MegaMan Trigger to focus solely on serving the Master and to ignore his "illogical" words, as she believes they were only created to serve the Master. Despite the repeated warnings, MegaMan Trigger manages to bond with the Master and was taken to Terra on request.
However, as the Master was unable to survive outside Elysium, and as such dies. As a result, MegaMan Trigger was labeled an aberrant, a unit that threatens the Master System. Fulfilling the dying wish of the Master, MegaMan Trigger fought Sera, Yuna, and the others to destroy the system.
However, Yuna decided to took a neutral stance in the battle. Sera, frustrated at this, headed to Terra to take matters into her own hands, and to eliminate MegaMan Trigger. However, she was unable to bring out her full power, and fought Megaman Trigger on a standstill. Both used all their energy in their battle, which almost destroyed Mega Man's body.
Following the battle, Yuna seal both inside the stasis field. She imprisoned Sera in the Forbidden Island alongside her Servitor unit, Geetz, and reset Mega Man and sealed him on Nino Island alongside with Data.
The events would be remembered by the carbon as an old legend. A tale about two goddess that watched over the world, the Sky Goddess, who guards the record of the ages (who is Sera), and the Earth Goddess, who guards the keys (who is Yuna). They argued when the Sky Goddess attempted to borrow the keys and was imprisoned as a result. She would be watched by Yuna for years, even after sacrificing her own body to save an carbon women.
Mega Man Legends 2
While Mega Man Volnutt was on a mission to save the Sulphur-Bottle, he accidentally released Mistress Sera and Geetz. Both were taken to the Sulphur-Bottom, where they were greeted by Verner Von Bluecher. Geetz told them that they need the four keys to unlock the Mother Lode, which would allow them to have ancient technology and be able to produce infinite amounts of Refractors.
Sera decided to focus solely on obtaining the keys, knowing Yuna wold not yield the keys, while ignoring Mega Man Volnutt, who was searching for the keys by the request of Bluecher. When Mega Man managed to obtain the last key, the Sulphur-Bottom was attacked by Sera and Geetz to steal the keys in order to open the library in Elysium and begin the Carbon Reinitialization Program.
Sera heads to Elysium while Geetz battles Mega Man for the Master's genetic sample. Yuna, along with her servitor unit, Gatz, tries to intervene, but as Yuna was no longer in her original body, Sera was unable to recognize her authority.
Sera succeeded in returning the Elysium, who was followed by Mega Man after being repaired from his battle with Geetz. When he confronts Sera, she reveals she was jealous of Mega Man's relationship with the Master, as she was unable to understand why the Master trusted Mega Man so much. She also said that, while she could start the Carbon Reinitialization Program, she didn't as it would be beyond the system limits. She also hold off the program to defeat Mega Man, believing defeating him would rid her of her "troublesome emotions.
As Mega Man manages to hold his own in the battle, Sera was suddenly interfered by Gatz, who invaded her internal system. Sera, however, was able to resist the sabotage attempt by unleashing her full power, which killed Gatz in the process.
Sera, in this form, battles with Mega Man, but was eventually defeated. She stated the more devoted she was in serving the system and the Master, the sadder the Master seems when he looked at her. It was at this point she finally understands what they wanted (a little), and stated the Master would probably smile at her the same way he smiled to Mega Man
Yuna suddenly appears and ask Sera to transfer her program over to Yuna's original body before her shell stopped working. Stating that Gatz died because of her gambling, and that no one would be able to keep her company if she dies.
As the Elysium is no longer in function, the Old System, which was shut down by the Master's people, begin to reactive, and being Sera's duty to watch over it, if Sera dies, it would took over the Terra, putting the Master's sacrifice in vain.
Convinced, Sera transfer herself to Yuna's original body, at which point Sera smiled at Yuna, which Yuna commented by saying she doesn't remember the last time she saw Sera smiled. both Mega Man, Sera, and Yuna need to return to Earth, but the game ends with them trapped in Elysium, as they wait for Roll and Tron, who was trying to send them a ship.