Rapid is a new character introduced in Metal Slug Attack.
A Rebel Army officer in charge of their supply unit, Rapid is also the best train conductor in the Rebel Army, as no one is able to best her in steering trains. Her map route and schedules are also known for being impeccably accurate. She loves transporting supplies and the vehicles involved in doing so, preferring nimble trains compared to bulky ones.
In battle, Rapid hitches a ride on the outside of whatever vehicle she is using and issues commands via hand motions and blowing her whistle. Normally she uses a simply Subway train outfitted with a cannon at the top, but this changed to the K-O3 Coupled Armored Vehicles once they were built, and later to another train when she was put in charge of leading the Supply Corps.
She has a successful military career, but her personal life is a mess due to numerous gossips and rumors flying around her. Though she appears to be somewhat aloof and carefree, she loves her position and will not tolerate anyone that threatens her work duties. If there a person that Rapid likes, she will ask them if they would like to board her train.
First appearing in the Extra Ops "Supply Lines", she's informed by a soldier that Abigail has tasked her with disrupting the Regular Army's supply lines so she can defeat them in a decisive battle. Rapid spots Vita flying about and convinces her to help out with the task. Vita takes down a new model of the Regular Army's helicopter, though Rapid states that she prefers modesty. Despite this, she asks Vita if she would like to board her train as they depart back to base, where she gives Abigail a bill to cover the cost of the mission.
Rapid later obtains the K-O3 Coupled Armored Vehicle to protect her supply convoys when one of them is attacked by the Martians. She encounters the Gemini Twins, angered that the enemy is attacking her trains. She manages to wound White with the K-O3, causing the twins to run away from her.
As the war intensified, Abigail later put Rapid in full control of the supply corps to showcase the strength of the Rebel Army. Initially hesitant as she is not interested in such, she eventually takes it to oblige her duties as an officer and continuous access to the armory. Due to being able to access the armory on a whim, Rapid quickly modifies a century-old train with powerful weapons, armor and engine. She later attacks a Ptolemaic Armored Crawler with her subordinates, intent on playing a slow game, but warns her soldiers that she won't stop for them if they lag behind.
Rapid appears in "We are the Mars People Rangers", where she is tasked with maintaining an Iron Cab when Abigail and Beatriz arrive to inspect it. Upon hearing of Martian invaders, Rapid offers her assistance to the two, though they refuse and tell her to hasten the Iron Cab's repairs so it can be deployed to assist them.
- Although she runs away upon being defeated, Rapid has unused death sprites. This similarity is shared with Nantes.