Comment by Iammeee on Kenja No Mago - Chapter 1

Shin is just toooooooooooooo powerful

Hypersonic Vibration on his sword, AKA a Vibro Blade,

"Vibroblades" or more commonly known as ultrasonic blades already exist in real life. They use some sort of vibrational element, typically a piezoelectric module, to to vibrate a blade at ultrasonic frequencies (~40kHz). Most commonly they are used for fine detail hobby work or manufacturing. An ultrasonic blade cuts material (like foam board, cloth, wood, etc) because the ultrasonic vibrations cause the blade to oscillate back and forth, mimicking a cutting or sawing motion on the macroscopic scale.
https://worldbuilding.stackexchange.com/questions/169317/design-for-a-working-vibroblade

TLDR: scfi wise It vibrates allowing it to tear things apart at a microscopic level, think of it like this, his sword is constantly listening to "rip and tear until it is done" and blessed by the DoomSlayer himself to rip and tear things apart atom by atom.
IE he's using his knoledge from his past life to use science to make his sword overpowered.