This is super insightful, thank you! It does suck that there's still much to be learnt about resonance... That is the main reason I initially considered X'enik's aether to be corrupted. I'm not sure how realistic it would be to have an alternative where the experiments done on him were for imperial gain to see if they could research and find a way to manipulate their own aether? That was more or less my original idea, since it's also what I thought would cause him to go blind but that can easily be worked around.
I like the idea that he may be unable to use fire aspected aether/magic if it's too potent etc as well.
With Y'shtola, I can see what you mean. It would be beneficial for X'enik as a hunter and a marksman to have an ability like that as well, but implementing something like that as realistically as possible with so little info to go off is difficult.