
Well, considering one of the Hearers never becomes involved with the Void in game, we don't really have lore that would point one way or the other on this aspect.
What I can say is that, unlike White Magic, Conjury is not lorded over by Elementals. Conjury was taught to Man by Moogles as a way to commune with nature. Man was then able to hear the Elementals, as They are the lifeforce of that nature. But they cannot stop us from drawing upon their lifeforce just as they could not stop the Black Mages from doing so in the War of the Magi. Conjury is actually used against Elementals and corrupted Sprites several times throughout 1.0 and 2.0.
So if your character became enthralled by the Void, would they stop hearing the Elementals? Yes, probably, your character would likely start hearing the call of the Void instead. But mechanically, it shouldn't affect your ability to draw from the aether in nature. Your slide into Thaumaturgy, on the other hand, might because of the two magicks being near polar opposites mechanically. One using an organic staff to draw from nature, the other using an enchanted gemstone to focus one's aether within themselves, which got discussed a bit in this thread.
Would dealing with the Void incur Greenwrath? Most likely! One of the major points of 2.0's CNJ storyline was that Voidsent were corrupting the forest and creating corrupted earth and wind sprites. If your character was Voidtouched, you might also begin causing the Wood to become corrupted, incurring Woodsin as you walked along. This Woodsin would likely culminate enough so that the forest and its denizens would attack you and try to silence your sin before you incurred Greenwrath, which is committing an act so damning that an Elemental decides to awaken and deal with the threat Him/Herself.
Again, would this hinder your ability to draw aether from nature around you. I would say no, but a cool thing you could play with, is that every time you do draw from nature, you start to corrupt it. Which might compel you to begin practicing Thaumaturgy in earnest, so that you can heal without using the aether around you, instead using only your own. Not risking further corruption.
Hope this helps! ^^; Sorry it's mostly speculation!
What I can say is that, unlike White Magic, Conjury is not lorded over by Elementals. Conjury was taught to Man by Moogles as a way to commune with nature. Man was then able to hear the Elementals, as They are the lifeforce of that nature. But they cannot stop us from drawing upon their lifeforce just as they could not stop the Black Mages from doing so in the War of the Magi. Conjury is actually used against Elementals and corrupted Sprites several times throughout 1.0 and 2.0.
So if your character became enthralled by the Void, would they stop hearing the Elementals? Yes, probably, your character would likely start hearing the call of the Void instead. But mechanically, it shouldn't affect your ability to draw from the aether in nature. Your slide into Thaumaturgy, on the other hand, might because of the two magicks being near polar opposites mechanically. One using an organic staff to draw from nature, the other using an enchanted gemstone to focus one's aether within themselves, which got discussed a bit in this thread.
Would dealing with the Void incur Greenwrath? Most likely! One of the major points of 2.0's CNJ storyline was that Voidsent were corrupting the forest and creating corrupted earth and wind sprites. If your character was Voidtouched, you might also begin causing the Wood to become corrupted, incurring Woodsin as you walked along. This Woodsin would likely culminate enough so that the forest and its denizens would attack you and try to silence your sin before you incurred Greenwrath, which is committing an act so damning that an Elemental decides to awaken and deal with the threat Him/Herself.
Again, would this hinder your ability to draw aether from nature around you. I would say no, but a cool thing you could play with, is that every time you do draw from nature, you start to corrupt it. Which might compel you to begin practicing Thaumaturgy in earnest, so that you can heal without using the aether around you, instead using only your own. Not risking further corruption.
Hope this helps! ^^; Sorry it's mostly speculation!