It had to be known that the Wang Family's treasury contained fewer than a hundred Top-Grade Spirit Stones. Using Top-Grade Spirit Stones to set up a formation would greatly increase its power. Those ancient and powerful factions with long inheritances all used Top-Grade Spirit Stones to establish their Sect Protection Formations or Clan Protection Formations.
Of course, Spirit Gathering Stones were indispensable.
There were twenty Spirit Gathering Stones here. They could slowly absorb spiritual energy and recharge themselves automatically.
No wonder the formation's power remained so formidable after all these years.
It was just unclear whether this great formation before them protected the island or the Flying Dragon Hall. The difference between the two was enormous.
If it was an Island Protection Formation, then taking away these Top-Grade Spirit Stones would cause the restrictions on the island to stop operating. That would make it easier for Liu Tianyan and the other three to search for treasures.
"Replace the Spirit Stones first. In any case, we're already here."
Wang Ruyan took out High-Grade Spirit Stones and replaced those whose spiritual energy had been exhausted. If this formation was an Island Protection Formation, all the restrictions on the island would become stronger as a result.
That would make it even harder for Liu Tianyan and the others to retrieve the treasures, indirectly helping them with their own treasure hunt.
Based on Wang Ruyan's years of experience, there was a high chance that this great formation was an Island Protection Formation, though she could not rule out the existence of other formations.
After the Spirit Stones were replaced, the formation began to shake violently.
On the surface of the sea, the disciples of the Heavenly Fiend Sect were standing guard.
More than a dozen streaks of escaping light flew over from the distance.