Rui smiled inwardly at Master Vertol's reaction. He sat down cross-legged, relaxing while simultaneously activating his stamina metabody, drastically lowering his energy consumption.
"You…" Master Vertol stared at him with pure bewilderment.
"That Yin-Yang technique of yours…" Rui smirked. "…Is it tiring to constantly maintain?"
The Martial Master froze as his eyes widened.
"I asked myself, 'Why does he constantly keep maintaining the Yin-Yang technique instead of only activating when an attack is incoming?'" Rui spoke out nonchalantly. "There are several possibilities, but…"
His gaze met Master Vertol's eyes.
"…the most likely one is that the technique cannot be activated rapidly."
Master Vertol did his best to suppress any reaction that he had, but unfortunately for him, Rui had already created a SOUL model on him.