In one of the other threads someone stated that vergil doesn't physically appear in human in this game but he is still there as we can see throught the final trailer. However i think that i have found something out here. In dmc 3, dante's sword awakened his devil form. In this we see that the weapons dante and vergil got from there father was technically binded to them to unlock their demon blood once there blood touches there sword. Now i am not a big supporter of the whole "The devil bringer is Vergil" theory, but i will say that that is the only explanation to this. Now in one other thread someone asked on the final dt forms like how sparda has his demon form, and said that he wants to know what dantes and vergils is. I stated that the dmc 2 majin form(ddt aka) is dantes and nelo angelo is vergils. I now see that i might have been wrong on vergils dt. We see that neros devil hand is stabbed but we don't see any blood, but if there was blood, then maybe it dripped on the yamato (the katana has all the same features, i would know i am a freak on vergil,dante,nero, and sparda) and caused it to activate the devil trigger. However, maybe the blood must drip on the blade while they are in dt to give the twins the full dt. If the db=vergil theory is right, then the devil we see nero controlling is vergils true dt. But this is all theory. However i do see a huge role for the yamato in this one so vergils spirit will be in this game. Only have to wait two more months and our questions will be answered.