Wallin fought in the Pendulum Wars as part of the 25th Sherrith Cavalry. After the Armistice between the UIR and COG was put into effect, Wallin was given leave and returned home to Mattino Junction after stopping at a base in New Sherrith.
- "I'm sorry. Richie Wallin. They've logged his COG tag."
- — A Gear soldier to Dizzy Wallin
Six weeks after the armistice, the Locust emerged and attacked all of Sera. Mattino came under attack as well, and the COG did its best to try to evacuate the city. However, most civilians were unable to leave, and Wallin was killed defending the city, and his mother Lena was murdered by the Locust.