Theoretically even if it would only target threats the protection is still nearly useless since the bolts travel way too slow and often miss the target when it's moving.

Considering you get it in the black metal phase of the game it is way too late to provide any meaningful protection against enemies you can't already handle and don't bother using it as anti-air artillery against Gjalls it doesn't do enough damage to keep you safe and likely it will miss all the shots anyway.