In the video above, we follow “Darwin,” who goes by a code name and is one of Ukraine’s most skilled—and deadly—drone pilots, with over 300 confirmed strikes on Russian positions.

The 20-year-old resembles many in Gen Z: He sports a scruffy man bun, plays video games and is often seen puffing on an e-cigarette. But once his shift begins, he operates with cold precision.

As drone warfare in Ukraine has exploded, his abilities have become crucial to the country’s defense and are reshaping the face of war.

Over a period of three weeks, I embedded with Darwin to document how tech-savvy young people like him are using rapidly evolving drone technology to target Russian forces along Ukraine’s torn front lines.

“It’s incredibly difficult,” he says, reflecting on the heavy toll of taking so many lives. “If I don’t do it, they’ll kill us.”

For the video, I travel with Darwin and his unit to experience how drones are changing the nature of warfare and how Darwin and his team are redefining the future of how humans will fight.

Write to Ben C. Solomon at ben.solomon@wsj.com