Ok huge apology to anyone who read my previous post and possibly started worrying, I never did play LoS 1, I briefly have before, but I was not aware of sub weapons being in that game at all period. I have no way of knowing anything at this point, again apologies.
So this is the case and anyone please do correct me if I am wrong, In Lords of Shadow 2 we are actually getting two new main weapons. I guess when they say Light magic and Shadow magic is being replaced with Void and Chaos, that could mean anything, I guess we don't really know yet for sure.
So theoretically one sub weapon could change the properties of all 3 weapons.
So one specific sub weapon while using the Void sword could possibly give us the projectile ability the sword has in MoF *Example*
Then one specific sub weapon while using Chaos Claws could give us some fire AoE *Example*
Then one specific sub weapon while using the blood whip could potentially give us a dash teleport. Maybe Dracula's iconic 3 projectile ability too *Example*
Far as mist form is concerned, yes I could see mist form being used for stealth in the game or in the modern day setting of the game, it was stated, so I don't see why not.