Tangible Ability - I

In the expansive backyard, the rumble of deep thunder echoed intermittently.

Of course, it wasn't real thunder striking the lower district, but rather the sonic booms created by Seraphina's punches. 

Even though there was no opponent in front of her, no visible destruction, and not even a hint of a shockwave, the delicate and seemingly harmless punches produced a deep, resonant sound that reverberated through the courtyard.

"Hoo..." 

Wiping the sweat off her brow, Seraphina exhaled a hot breath. She had been using a new method she had devised to temper her body—compressing the immense strength of the head of strength within herself instead of unleashing it outward. This method, which could be described as suicidal, allowed the force to rampage internally, refining her body. 

How she came up with this method, managed to implement it, and even saw significant results … is best left unexplored for the sake of safety.