Every member of Eizenger knew that those castles were similar to the crystal castle which was the base of their own guild. The only difference was that this castle was left with ruins and destruction.
The crystals in this dungeon were shaded from light blue to navy blue. The navy blue crystals were not very large. The largest one was about the size of a player's head. But the light blue crystals were different because some of them were almost as large as the Crystal Castle. Because these crystals emitted light, there was enough light to see inside this giant hollow.
Every enemy that appeared in the path at the beginning was a giant reptile with a crystal body. Its size was as big as an aircraft, but only one came out at a time. And because Tan's party was strong, allowing the players to invade through with no difficulty. But it still took longer than Tan claimed. In conclusion, they wasted about an hour on that part.