Nero nearly lost his composure as he observed his innate card at the end of the night. He had spent some time killing the roaches in various ways, testing not only how the condition of the body affected how much aether he could absorb, but also how he could use the card most effectively.
As it turned out, as long as he used the card on himself, its effect would stay active for a few minutes. Within that time frame, whenever he touched any dead roach he would absorb the vitality from it. Alternatively, he could directly target the body, and absorb the vitality from it remotely.