While the final judgment of each competition was always presided over by an Emperor, it was the Ancestral Court that decided which Emperor it would be. The fact that the White Tiger Great Demon King had managed to secure this position clearly indicated the considerable effort and influence he had exerted.
His presence alone served as a testament to his recognition of Pretty Girl. Although Big Cat also possessed the bloodline of the Tiger Demon Clan, how could Big Cat be closer to Pretty Girl, who carried the White Tiger Great Demon King's own bloodline? Therefore, it was obvious he was there for Pretty Girl. Even if Pretty Girl lost the match, she would still be afforded his protection. With the White Tiger Great Demon King's presence, at least during her time in the Ancestral Court, she wouldn't need to worry about her safety.