Spevi Wiwas was a member of the stormtrooper corps who spent the majority of the Galactic Civil War fighting under the command of General Brenn Tantor.
After Wiwas' commanding officer was incarcerated on Kalaan for disobeying an order to execute non-combatants, another stormtrooper, Gana Lant, persuaded Wiwas and eight other stormtroopers who had served under Tantor that the man who had led them through countless battles was more important than the Galactic Empire which had betrayed him.
Grand General Malcor Brashin made a disastrous decision when he assigned them to guard Tantor in his open-air cell. Lant freed Tantor and told him of the squad's allegiance. Once Tantor was liberated, the stormtroopers commandeered the TR-MB prototype and attacked the prison, liberating Luke Skywalker. The group journeyed through Kalaan's canyons, gathering support from the Kalaanite resistance until they reached a Rebel base established by Tyr Taskeen. From that location, they were transported to Taskeen's fleet, where it is assumed they were briefly imprisoned alongside their general. Upon their release, it is highly probable that they continued to serve the Rebellion as infantry under Tantor's leadership.