- "Those are Sentinels, master. It seems as though they can detect magical creatures." — Gnarl warns the Overlord of the Sentinels in the Everlight Facility.
Sentinels are hooded humans, who work for the Glorious Empire and use special staves to detect magic. They are often found atop guard towers or other high points, and they never come in direct "contact" with the player., except in one cutscene where several Sentinels teleported in and surround the Overlord, activating the anti magic field and successfully captured and sent him to the Arena to fight.
They use their staves to detect if a creature is magical or not. If it is, then it is sucked up into the machine of Eradicator Agents.