Headshot kill for sure...if the player plays strategically, he will keep to cover and avoid open areas which snipers will keep a watch over. Additionally, with movement abilities like "blink" it should be pretty challenging to get a headshot. A sniper is meant to be lethal and two shots to the head for a kill would be unrealistic...even for a magically enhanced being. "Shields" could play a role in diffusing this but we'll just have to see.