The word "universal" means something that applies to all or is widely accepted. Antonyms for this word, therefore, would be specific, individual, or exclusive. The word "jet" implies speed, power, or aviation. Antonyms for this word, in contrast, would be slow, weak, or terrestrial. Putting these antonyms together, we could create phrases like "restricted ground" or "unique crawl" to counter the original phrase "universal jet." These antonyms suggest a limit or exclusivity, which stands in stark contrast to the overwhelming reach of a universal jet.