EARLY LIFE
Before the events of the series, Zukai was a member of the NESF and was in the School Wars. Shortly after, however, he joined a different war, the Changeling Wars. There he would rise in the ranks until he became a Super Saiyan.
PPG SAGA
From time to time Zukai and his cousin Brandon would check earth for capable saiyans to fight in the war. Seeing the Cousin Trio as the strongest Saiyans on the planet, the two land near the E-Fighters' training sight and arrive to explain and give the offer.
After Brandon explained the past of the Saiyans and Corey hearing that the Changelings were involved, Corey stepped forward and transformed into a Super Saiyan, asking if it would help in the war. Zukai states that there was a piece of irony, the peace loving Saiyans gaining a power. Afterwards he transformed into a Super Saiyan himself (at a faster pace than Corey
could), joking at how the form used to be a legend of the Saiyan race.
THE TWO BROTHERS PAUL-ZUKAI
SUPER SAIYAN TURNS ZUKAI
Brandon, seeing the reactions of the E-Fighters, states that about half the Saiyan army can transform into Super Saiyans, as well as the rest being able to transform into a lesser form of the Super Saiyan (Most likely False Super Saiyan).
THE BROTHER OF PAUL
Corey wishes to see what the Saiyans can do, challenging Zukai.
Zukai asks if Corey wants a "quick match," because "It'll be just that".
Zukai proceeds to start the fight, launching Corey into the sky. After a short exchange of blows, Corey uses the Light Speed Attack, flying past Zukai and coming to a quick stop. After a short pause, Corey gets blitzed by numerous blows causing him to fall and revert to base. Thus the cousins agree to fight in the war, but leave the Eds to stay and protect the Earth.