During his time at Sobukhazi, Mzila made the pivotal decision to join the Zimbabwe War of Independence, fighting with the ZIPRA, which was the armed wing of ZAPU.
He received military training in the Soviet Union, Cuba, and Angola, eventually becoming a ZIPRA platoon commander operating along the Zambia-Zimbabwe boundaries.
During the period between 1982 and 1987, the country experienced the Gukurahundi genocide, where ZANU targeted dissidence among ex-ZIPRA militants, resulting in massacres of the Ndebele people in their homeland of Matebeleland.
He gained prominence as a representative for the victims of the Gukurahundi massacres, addressing audiences through rallies, funerals, church functions, public meetings, and even Parliament.
In 2018, Mzila was denied a visa to visit the United Kingdom to discuss the Gukurahundi massacres at a St Andrews University event.