Little did the red-eyed being know, but the hidden entrance to the real core of the World Beast Formation had already been found. Red was right. The island in the center was just a death trap. The World Beast Formation did indeed use the demon beasts' blood, but there was no such thing as it using souls. That's something the red-eyed being added later to capture the Souls it needs.
If Rean's group really entered that opening on the island, they would meet with all the trapped souls in there. Be it the twins or even Frin and Duran, they would be assaulted by the souls all at once. After all, it wasn't as if there was enough demon beast blood for all the souls. Some of them had been in that place for almost as long as the red-eyed being was in the Dimensional Realm. One can only imagine the instinctual grievances they felt after being trapped there for so long. They didn't have sentience anymore, but their wrath still remained.
