i finally got his ass a lil while ago.. an jus read your post an its basically exactly what i did except for the bow, i tried to use the bow to get the kryll to get away from him but there only off em for about as long as it takes for you to switch weapons.. i jus used the lancer and the sniper rifle an i'd shoot em with the sniper at a distance an when he was hella close to the barricade i jus blind fired with the lancer over the barricade right in his face. i'd actually get 2 clips off on him before he came around the side of that shit an i hadda mob out to the other one on the other side of the train.. shit was frustrating until i figured it out tho