Spirit cruisers were commonly seen in the 12 Empyrean Heavens. After all, not every warrior was proficient in spatial dimension laws or had the ability to do Void Transference.
If they needed to make long-distance space travel, they could only rely on spirit cruisers, using the arrays in the spirit cruiser to tear the void.
Yi Yun found it incredulous that he would encounter a spirit cruiser. He vaguely felt that he had stepped into the 12 Empyrean Heavens. The number of warriors in the 12 Empyrean Heavens numbered like the number of grains of sand in the Ganges river. But when it came to the space around the 12 Empyrean Heavens, the number of spirit cruisers were extremely few in number. He found it hard to believe that he had encountered a spirit cruiser as he reached the end of the rope.