Whilst this concept intrigues me, I do have a few inquiries on topics the post isn't really clear about or otherwise doesn't clarify.
1. Do these 'words of power' affect arcane casting (i.e. power, precision, etc.)? If so, I find this rather unbalanced and impractical as it implies a mage must expose themselves and in short they must learn a completely new language just to operate their spells. I don't think many of us want to jump back onto the forums, delaying roleplay just to make sure we didn't spell or pronounce a word wrong. However, I think it would be a promising aspect if it's just optional for the sake of literature value. Otherwise I don't actually see a need for this to affect the magics themselves. In my opinion it will confuse and disorganise magic roleplay.
2. Following on from my argument in the first point; won't this render voidal magic practically inferior and imbalanced to dark or deity magics?
For the sake of a balance argument, if these 'words of power' are forced upon voidal magics rather than being optional, wouldn't this be a disadvantage against dark magics and deity magics? In a sense it restricts voidal magics compared to these two types and establishes a ridiculous narrative that makes magic roleplay even more convoluted (as I mentioned prior). Once again, this is based upon the idea it's forced rather than optional. Some people enter the world of magic roleplay for a silent and more subtle approach, rather than shouting random and unclear words.
If possible, I would appreciate a response so there might be less confusion and greater clarity for me to establish an overall judgement.