In the Series Edit
Riko was first met in South Carolina, where she'd been harassing soldiers with her levitating spears. She was then met again by Lars and Gyro after she attacked them during their escape from Eddy's warehouse workshop in South Carolina. She ended up losing her hand to Swift after he shot it off while coming to check on the soldiers. She ran away after sustaining the injury.
Riko showed herself again during the South Carolina Resistances fight at the docks. There she attempted to kill off the Resistance soldiers but was quickly out-manoeuvered by Lars and Gyro, resulting in her capture. She spent a short time at the South Carolina Resistance Base before she was broken out by Yami. She then met Gyro, after he was captured, at the Arume Base in South Carolina, before flying him to Italy with her. Once in Italy, she got her hands on some new spears, just before the Matterhorn Mountain Arume Base was attacked, she lost Gyro in the attack.
Riko was a stuck-up, aggressive Arume most of the time, all of the time when dealing with humans. Despite this, she was very strong-willed. Her hate for humans and the Resistance was extremely powerful, too. It was so strong, in fact, that she kept fighting all alone after the Matterhorn Mountain Base was destroyed, even while starving and freezing, till her last breath.