Dark Realm...
Everyone must have guessed by now that this is an S-level anomaly.
However, this anomaly differs from those we've previously encountered; it's not fixed in any specific location, nor does it have a physical form, and it certainly doesn't exhibit any regular patterns of appearance... The only way to detect it is through a type of "wavelength" that only those old heads in the "Research and Development Department" can comprehend... Of course, even if they explain it to you face to face in the most elaborate terms, you wouldn't understand. In any case, according to them, the greater the variability of this wavelength's frequency, the higher the probability of this anomaly's invasion.
Beyond that, there are no other methods.
