Hruga's Seal

The divine seal that holds Hruga's power is called the "Core of Stellarium."
Those who bear it are "Seal Watchers."
There are two Watchers in total—Tina is one of them. That's why the Council assigned guards to protect her.

The recent Tales of the Plains were likely attempts by Hruga's follower, the "person in black," to break the Stellar Seal​.

It becomes clear that the Tales of the Plains, the attack at the ceremony, the person in black...
All these evil acts trace back to the witch Hruga, who now seeks to shatter the Stellar Seal​ on her through her follower, the person in black.