Tobii EyeX is an eye tracker that can enhance your VR experience into the game, it has many possibilities in a game like this and I would love to see it implemented.
To give you an idea: https://www.youtube.com/watch?v=UJEA9Z3SaUo
I think it is easy to imagine a combat where your opponent could predict your next attacking because your are looking at his right or the possibility to trick him. And based on what I have being hearing about Tobii they would love to colaborate.