After consuming the Thousand-Blade Blood Dragon Baby, Han Sen spent some time researching the energy flow of the blue bell. If he could simulate its energy flow, he could absorb its Life Geno essence.
Han Sen used Dongxuan Sutra to simulate Death Knell's energy flow and felt his entire body vibrate. He heard the sound of a bell ring, and his body throbbed to its chime.
Han Sen flicked his arm, which generated a noise not unlike the Death Knell. The bell sounds no longer affected Han Sen, but they made the Golden Roarer by his side shake.