The zooming in was all it was this time, with the physiological changes. Perhaps the desire to kill came mostly from being on a battlefield surrounded by others. It will present problems later though.
For future reference, if the characters receive any kind of outer influence it'll be detailed by me in a post or maybe by PM, so if it's not said that there's some intense, unnatural desire to kill, then don't worry about it for now because there isn't one.