C1045 Encountering the Whale Emperor

Of course, don't think it's easy for Su Yun to break through just because it's so easy. In fact, once one reached the Prehistoric Stage, every breakthrough would be small. The energy required to break through a small realm would be very long and difficult to estimate.

The reason Su Yun was able to break through so easily was because he had been accumulating energy for a long time.

However