The method of military formations would be integrated into the things that one would often control and closely related to when they were alive.
This also meant that the Tiger Tally might have been integrated into King Sheng You's military formation.
As for how the eighth prince knew, it was because of the content that the eighth prince was in charge of.
The Eighth Prince was in charge of the access to the royal treasury.
Although he was in control of the world, he did not dare to move recklessly.
When King Sheng You died, the items that entered the royal treasury were related to King Sheng You, but there was no Tiger Tally.
There were only two possibilities.
One was that the Emperor kept it for himself. After all, the importance of the Tiger Tally was more valuable than most of the things in the royal treasury.
The second was to be buried with King Sheng You.