Complex sentence: First mentioned by the robot Ultimate Vision, Gah Lak Tus is shown to be a group mind of city-sized robotic drones which attack worlds via envoys (similar to the Silver Surfer) who introduce a flesh-eating virus.
Split into simpler sentences: First mentioned by the robot Ultimate Vision, Gah Lak Tus is shown to be a group mind of city-sized robotic drones. The group mind attacks worlds via envoys similar to the Silver Surfer, who introduce a flesh-eating virus.