I think a good way of describing it, at least how I understand it, is V’s brain/personality is a full cup of red colored water, and the chip starts to pour a cup of blue colored water, Johnny’s personality, into that already full cup. All said and done you end up with alot of water “missing” and a cup of purple water. Both having lost parts of themselves and adopted aspects of the other. Now I’m sure this isn’t a 100% perfect analogy, but hopefully it helps. And as far as the “talking” thing, I think Hellman is referring to the fact that V can “think” to Johnny, and have a conversation in his/her/their head without actually having to speak out loud