Ha, maybe I was right last week. Julius was probably just pissed off that Toa was bigger than he was. But Julius is a roided up freak while Toa was probably natural (though naturally gifted) his entire life. Julius was also noted to be very intelligent (at least in anatomy, nutrition, and sports physiology). He probably has Toa's techniques figured out.
Or Julius just used double blast (blaster??) core. Wakatsuki needs to learn the blastest core so that he can get ahead.