Human organs are quite sensitive to infrasound, and exceeding the tolerance limit can cause significant damage to the kidneys. During World War II, there was a case where a German unit's soldiers hid in a bunker to avoid shelling. It was only after the shelling ended and the Allies captured the position that they discovered these soldiers hiding in the bunker had not been hurt by shrapnel, but died from internal bleeding caused by the infrasound generated by the landing shells.
Since then, research on sonic weapons began to be scheduled.
In Huaxia, this research has continuously been a top priority, and the first actual application of the weapon developed after many revisions wasn't in war, but rather on an unknown health group.
After enduring life-draining battles, talisman swords, close-quarters broadsword users, Heavenly Stems, and even the group leader Zhang Liang taking action, the enemy held out until the very last moment, leading to another final exhausting battle.
