When combat training entered the stage where Chakra was used, the battles between Shisui and Obito became even fiercer.
A Breathing Technique without Chakra and one with Chakra were practically two entirely different levels of intensity.
Greater strength and speed, accelerated Chakra Nature Transformation—these were all boosts that directly increased one's raw power.
When Obito and Shisui's battle reached its peak, flames were flying almost without pause.
Nature Transformation Ninjutsu of the same attribute followed a one-to-one cancellation principle. In other words, flames converted from one unit of Chakra could block flames made from one unit of Chakra.
When Mu Yue had first transmigrated, Obito, being older, had slightly more Chakra than Shisui. But Shisui later trained more diligently and awakened the Sharingan as well, so his Chakra had long since surpassed Obito's.
He could not match him in taijutsu, and now he could not match him in Chakra either. As a result, Obito felt even greater pressure during the second stage of training. On the first day, he was defeated again before lasting very long.
Pressure brought motivation, especially since Nohara Rin would occasionally watch their battles during breaks. Obito's desire to impress her drove his motivation to the max. His Breathing Technique proficiency improved day by day, and he forcibly managed to last a little longer against Shisui through his more practiced Breathing Technique.
By the final day of the second stage, Obito had fallen into a disadvantage right from the start, and under Shisui's calm, swift assault, that disadvantage only grew worse.
Feeling that he was about to lose, Obito had no choice but to use Total Concentration Breathing to fend off Shisui's attacks.
But Shisui could use Total Concentration Breathing too. Obito was merely prolonging the time before his defeat.
"Damn it, Little Rin is watching.