Spectral guardian

The spectral guardians were spirits that guarded the Jedi monument on Rhen Var. During his search for Ulic Qel-Droma during the Dark Reaper crisis, Anakin Skywalker encountered them protecting Qel-Droma's tomb. Not allowing him to enter, Skywalker was forced to battle them in a TX-130 Saber-class fighter tank. He managed to dissipate them by destroying their tombs, which their powers were tied to. He then proceeded to retrieve the information he sought.

These mysterious creatures could pass through matter and create weapons of energy from the air.