Stelio Kontos
All Star
I don't think there is any explanation on how they created the creature other than magic, but it's sole purposes was to kill man...clearly somewhere along the line the white walkers got their own agenda and turned against the children, as I said, it's the classic "can't control your creation" trope. And at the core, they are still completing their mission of killing man
Kill man >>> Obey COTF
White Walkers probably realized the COTF were the ones keeping them in the North so turned on them
Also, was talking to the girl about it and I'm all like dam those White Walkers showed up conveniently quick and she's like well we don't know when in time Bran saw them and the White Walker grabbed him/put his mark on him...what if Bran's vision with them was like a month ago. And they been travelling all this time to get to the cave