Hi.
Is it possible for a character to wield both the Light and Void/Shadow?
Given that the Light blesses based on one’s convictions, and that the Void grants powers willy nilly as long as you’re willing to tune in for a constant barrage of edgy/corny whispers, could an individual manage to wield both powers, and perhaps in the process, balance him/her-self to some degree as to avoid becoming a zealot or mindless-slave to the void?
Discipline priests say hi! And every priest can learn a few minor shadow spells really. Maybe not Lightforged.
Pretty much this.
/waves in Disc Priest
There is no Good. No Evil. No Light.
There is only POWAH!
In Netherstorm there are even voidwalkers using holy spells. I bet that is not canon after all this time since TBC but as it is mentioned above it is possible to wield both to a balance. Yet I imagine that would prevent the caster from becoming increasingly powerful with either.
Their cousins are Lightwalker or something on those lines
It requires discipline (roll credits) because both Light and Shadow encourage you to rabbit hole and also have diametrically opposing views of the world, but it’s certainly possible. Even Anduin is capable of using Shadow magic and he’s so dedicated to the Light that he can mass ressurect.
Lightspawn.
Yes, those bright unit bois. 
Which has some implications. Well, potential implications. Lothraxion has gone on record saying that once you practice shadow magic, you’re eventually doomed by it - with the sole exception being the Locus Walker.
Now, I know better than to take his word at face value. He’s an in-universe character and nothing close to omniscient, but he does have experience as both demon and Lightforged. Not only that, but his charge in the Burning Legion was specifically to hunt and destroy Void related threats. Between his own and the Legion’s experiences, I do have to take his claim somewhat seriously.
Then again Anduin did pull a Mass-Lazarus at the drop of a hat, so maybe he’s beyond that sort of drawback. It might spell for an unexpectedly dark retirement plan for Disc/Shadow priests however. 
bold of you to assume that lore is going to remain consistent when it is routinely dropped like a boulder between expansions
magic bones
Wasn’t the whole thing between Alleria and Turalyon not being able to touch one another due to the fact that Turalyon was infused with Light and Alleria with Void, since they are opposites?
I suppose it boils down to just how much of either there is and there indeed needs to be a strict balance, so one does not overwhelm the other.
Or something, I’m not a priest.
https://i.imgur.com/OUUVEBW.mp4
They’re able to touch, just not when Alleria is all Voidy. IIRC. It’s detailed in the Shadows Rising novel, someone else is free to correct me on the details.
Just in general they can’t touch without pain - though as Turalyon is Lightforged he is a little more attuned to one end of the spectrum than the average bear (or priest)
At that point in the story Alleria was learning Void magic but hadn’t eaten a Naaru yet
So edgy you could cut veggies with it
Short answer: Yes.
Longer answer: It seems that being Lightforged, or infused with the Void, is a very different thing from just wielding Light and Shadow.
Forsaken -can- wield the Light, but are pretty much into their Shadow malarkey, and more tellingly, as people have mentioned, we have young King Holybones who is pretty damned good at this Light business. I’m not sure it is a mass Rez he does at Undercity, it looks a bit more like he is picking up mortally wounded and dying soldiers (A small distinction I know, but an important one) which is a very powerful feat indeed. We also see, in the Jade Forest that not only is he -able- to use Shadow Magics to manipulate minds, but that he is actually OK with the ramifications of brainwashing people who are acting in his best interests. He literally mind controls a rescue party, just so that he can carry on with his ‘Gap Year’ in Pandaria, which is, when you think about it, morally dubious as heck. Now admittedly, he does not have his Holy Bones ability at that point, but heck, I don’t have Holy bones, just Titanium ones, and even I can see that the ethics and morality of his behaviour are as sketchy as hell!
So yeah, it looks like it is not just a games mechanics thing, but is actually something possible lorewise also.
We’ve all been in those sort of relationships. Usually during a Goth Phase 
Thanks to all for all this feedback!
In terms of the potential power-cap, I suppose the “jack of all trades” term does indeed apply here.
Philosophy wise, this could generate an interesting dogma of sorts, one that promotes balance above all else.
Now my question is, could the two energies be combined in terms of say… “casting” a spell? Ex: you face target A, draining its essence, empowering yourself prior to smiting target B with righteous Light (draining essence since Void manifestations are known to be high-maintenance, i.e requiring consumption of other energy-types). Would this work in any way, shape or form? Am I correct in assuming that it cannot, given that last time void and light came together, “big-bang” came to be? (edit: that and oocly not being able to cast holy spells whilst in shadow-form(?)) - (edit 2.0: then again, oocly one can cast PW: Shield whilst in shadow-form. Is pwS not considered Light magic?)
It is a similar question to whether one can wield both fel and arcane. It is possible, but most often someone capable of wielding both will concentrate solely on one. After all, a lot of fel users were at one point arcane users.
I see this the same with shadows, having played a slew of shadow-wielding characters. It requires a mindset where a character is ready to throw social standing, trust and their own sanity under the bus in exchange for extremely powerful abilities. At that point, there’s seldom a reason why a character should “take just a few of those extremely powerful abilities with good measure”. That’s why I would consider discipline priests one of the rarest to find in roleplay.
True discipline priests, that is. Not those holy priests who use the occasional shadow spell.