Ukrainian People's Army
At the end of 1918 Hryzlo was in charge of an armored train operating in Volyn. He later came under the command the Northern Front of the Ukrainian People's Army led by otaman Volodymyr Oskilko. During Oskilko's Uprising, Hryzlo supported his commander. After the mutiny he returned home to the Cherkasy land where he wagedguerrilla warfare against the Bolsheviks' presence, reestablishing the Free Cossacks formations.