Pre-Islamic Oğuz Turks had a matron deity named ''Asena'' she was also the goddess of survival and wolves. Her domain in the heavens/sky was the star you know as Sirius, because of that, pre-Islamic Oğuz Turks were using either a wolf or a star symbol on their banners and flags to honor their matron goddess. When they converted to Islam, they just swapped the star with the Star of David or similar designs like it. The Star symbol on the wall is the Islamicized version of the ''Star of Asena'' commonly used by the Seljuk Dynasty and some of the Anatolian States before the Ottoman Dynasty unified them by force. The most important and powerful of these states was the State of Karaman, and their flag used that exact symbol. The story takes place roughly 200 years after Karaman's fall and the exile of their ENTIRE population to Macedonia. The assassin might actually be a survivor of Karaman seeking vengeance.