It’s official: Crossmauz is the greatest Twitch streamer of all time. There are few better feelings than getting the last kill in an intense Call of Duty game and securing the win for your squad. Some people stand up and scream in joy. Others do a little dance. But a rare, elite few decide to ignite a flamethrower. Enter Crossmauz, a 15-year-old Twitch streamer who has set up festival-grade lasers, lights, sound and pyrotechnics—yes, really—for his CoD celebrations. Taking place in what appears to be his small bedroom, after queuing up some hard dance music, he unleashes a barrage of laser beams, strobe lights and literal walls of flames that appear dangerously close to the ceiling and furniture around him. Onscreen visual effects blitz viewers as our star screams into the mic and lo...