Demons were creatures from another dimension. They would not simply appear in Firuman out of thin air. Someone must have opened a portal to the abyss and summoned them.
Where was the location of the portal? Who was the summoner? These were the things Link wanted to know.
After casting an unmodified Edelweiss spell onto himself, Link walked towards the demon and raised his wand. A Sacred Whistle appeared at the tip of his wand. The whistle spun at a high speed and released a piercing screech through the atmosphere. Visible air ripples could be seen around it. Link positioned it only around two feet away from the demon. As long as Link release the spell, the Sacred Whistle would pierce into the demon's skull and deal a fatal blow.
The demon was evidently becoming nervous. His bloodshot eyes stared at the whistle defensively.