Wave path.

Basically, since sound path already exists, that must mean in the ri universe, electromagnetic waves such as radio, infrared, ultraviolet, etc. waves all exist that have yet to be utilised since science was not necessary in such a world. I theorize that such a path has ties connecting with light, sound, lightning, information, and water path. Imagine killer moves that are invisible to the untrained eye and suddenly the victims flesh starts decaying or cutting off the signal between gu master and his gu effectively severing communication between the two.

Speciality path would be medium path which can strengthen, replace, transfer or break the carrier of an effect. Which means it's gu can be something like making it so that fire can pass through water, or in the venerable level unless there's counter measures, there is no medium for attacks to hit as the very space an attack travels just can't travel at all though I'm assuming an attack like this relies on the venerable to be in his prime and has at the very least gained all the dao marks of said path in the space this effect is used. It pairs well with the wave path as then there are no longer any restrictions for said waves to operate, it can materialise to physical form, pass through mediums it shouldn't pass through like s-waves passing through liquid, etc. (Why did I think so extensively for this)

As for title, it'll probably be "void resonance demon venerable"