Watcher

A Sentry Sentinel is an enemy featured in Skyward Sword. They, along with the Guardians, protect and patrol the Silent Realm. However, unlike the Silent Realm Guardians, the sentries are not affected by the Sacred Tears and thus will not be stunned by its power.

The Sentry Sentinels shine a light through the realm. If Link passes through this light, the Sentry Sentinel will emit a loud sound that will awaken the Silent Realm Guardians, canceling the effects of the Sacred Tears.