The black two-star token represented the presence of a Grand Mage. It could only be used by those who had reached Grand Mage as it was their identification token.
However, there were instances where the descendants of a Grand Mage would use the black two-star token to show that they were backed by a Grand Mage.
Furthermore, all black two-star tokens would have the power of a Grand Mage contained within it when it was created. It was one of the main reasons why the descendants of a Grand Mage or the Grand Mage's disciples would bring it with them.
A Grand Mage could seal a grand-level magic spell inside the black two-star token. However, only one grand-level magic spell could be stored inside the black two-star token.
The usage of that grand-level magic spell would remove the grand-level magic spell contained in it. In other words, the grand-level magic spell could only be used once and it was mostly used as a life-saving artifact.