The treasury was hidden behind seven layers of seals that could only be opened by someone with the keys. The seven keys themselves were split and handed to the Seven Shadows to keep. So unless all of them came together, the seals couldn't be opened, and no one could enter the treasury.
However, that did not matter in the presence of Shumi.
With a single touch of her palm and a burst of her All Ending Yin Qi, she could easily shut down any formation or seal, allowing her to go through them.
It was a problem if there were more than a single seal because they would fight back against her, making it difficult. But thankfully, the seals for the treasury were created with her powers in mind, and so the seals were at least a few meters apart.
So, they were pretty much separate seals that she could pass through one at a time.
