Ling Tian cared so much about increasing the power of his Externalized Small World not only because it could greatly strengthen various secret arts, such as Devouring the Starry Sky, but also because it could greatly increase the power of his grand formation. When his Externalized Small World merged with the formation, its power would rise dramatically, naturally boosting the formation's power as well.
Moreover, with Ling Tian's abilities, he could incorporate formation runes and restrictions into his Externalized Small World, thereby forming a grand formation. Although this formation would not be as powerful as the one he had set up before, it had one advantage: with a mere thought, he could incorporate various formation runes and restrictions into it and repair any damaged sections. In other words, he could keep the formation under his control to protect himself and his loved ones, without worrying that a Lord of the Universe would break through it.
It was easy to see why. Although the formation Ling Tian had set up before was very powerful, an external formation could still be destroyed, especially when facing a Lord of the Universe's attacks. And once the formation was destroyed, he would have no time to repair it. Without its protection, he and his loved ones would be under immense pressure from the Lord of the Universe's cosmic suppression. That could well become a hidden danger that led to their defeat, so Ling Tian had always been very concerned about this.
Although Ling Tian could have incorporated formation runes and restrictions into his Externalized Small World even back then, its power had been limited, and the runes and restrictions he formed that way would naturally have been limited too. Now, not only could he combine his Externalized Small Worlds with different attributes, he could also