Nova is a new unit introduced by Metal Slug Attack, a member of the Future Rebel Army who travelled to the past through the Big Gate.
Character Summary
A cybernetic clone of Vita, improved with the advanced technology of the Future Rebel Army. Although Vita herself is still alive in Nova's time, she's lost all mobility and has been confined within a life-support system. It's unknown as to whether Nova is autonomous or remotely controlled by Vita, but Vita does stick close to her "sister" in battle and will appear from underground (next to a single clone) should her twin's side achieve victory.
Compared with the original, Nova's power and durability are greatly improved, even though her basic movement patterns are relatively unchanged, while still being visually distinct. Just like the original, she shuffles across the battlefield slowly, suddenly leaping forwards when an enemy comes into range in order to deliver devastating combos. She no longer appears to be able to fly, however, and her two explosive eye-lasers don't have quite the same range. Her voice is of a slightly higher pitch than that of the original.
Similarly to Vita, should Nova be critically damaged, she goes on a self-destruct protocol to take any enemies with her, while revealing some of Vita's old wounds in the process.
Although Nova initially disliked Vita at first, she soon bonded with her original host in the present timeline after seeing that she was not what she expected to be. Throughout the events in both the Extra Ops and Another Story, Nova soon came to realize that she was Vita's only hope, and as such, devoted her efforts to ensure Vita's happiness.
Story
Extra Ops
First appearing in the Extra Ops "Next One", she is sent from the future to destroy the newly built Slug Gigant MK II, which she does successfully.
She later launches an attack against a Regular Army base with the help of a new Kraken. The attack is almost successful, but is repelled due to Mello's convenient arrival. The two share a few words before Nova makes her escape, as she states that she cannot be captured yet.
Nova returned to assist the present day Rebel Army with a special Kraken. They are attacked by the Ptolemaic Army, and Nova fights Lucy. Lucy's frog mecha intervenes and surprises Nova, prompting her to retreat and return to the future.
Nova later returns to the present after hearing a Rebel Army facility is under attack by a Great Moth, and she is the only one able to keep up with the agile Invader. Vita and Navy arrive soon after, and she appears to smile while looking at the pair, which a soldier interprets as her reason for coming to the present.
Another Story
Nova first appears in the story "Cleopatra's Pleasure Tour", where she is summoned into the present world while on a mission for the Future Rebel Army. Unsure of what happened, she investigates the nearby area, confused to where the enemies are. El Dorado appears and asks for peace, but because she is intent on finding the enemy, is forced to battle him. She is soon dragged away by Vita, where she admits that she did not expect her to be a cyborg and appears to share an unknown bond with her. After Cleopatra defeats Vita, Nova confronts her, but is dragged back to the future before a proper fight could begin.
Nova eventually returns to the present timeline in time for Christmas. However, because of her origins, she had no one to share Christmas with. Midori would eventually arrive and inspire the cyborg, who eventually realized she was Vita's only hope. She gave Midori the Christmas fragment that had flown to her.
Later on in the summer, Nova was sent to a resort island to act as a cheerleader, which she found embarrassing and wondered if it was actually a mission. When everyone on the island becomes aggressive, she attempts to defend the Rebel Army personnel from Rita, managing to snap her out of her trance by causing a mental breakdown. Odette, who had also arrived for the summer, informs the two of the situation and Nova goes with her while Rita stays behind to help the other Regular Army personnel. When Nova finds a Mars Brain Robot, she realizes that the Professor is behind the scheme and confronts him with Odette. After damaging the Rugname X, the Professor tells her that the boreal matter will wear off soon. She tries to chase him, but Odette drags her away as the Rugname X would have crushed her otherwise, much to her disappointment.