Within the Twelve Palaces, they never had a lack of capable people. Although the parents of Qiao Chu and his companions were strong enough in their own right, they were not considered to be elite in the Twelve Palaces. Besides the parents of the five of them, there were two others from other palaces who had also managed to find the Dark Emperor's tomb. What was strange about it was that the times these people reached the Dark Emperor's tomb had all happened within one day among them and congregated together within the Dark Emperor's tomb.
If it was said after immense hardship and they had been the one among a million who managed to find the Dark Emperor's tomb, that wouldn't be hard to explain.
But what was strange was that so many people had managed to go into the Dark Emperor's tomb on the very same day and besides that, regardless how many more people the Twelve Palaces sent out after that, not a single one had been able to find the place again.