Position yourself behind a rock on a fairly level field to hide from breath cloud attack. Slide out of cover shield down, they seem to cloud breath immediately if you are shielded. Shield up to reflect blue torpor shots back at him, if no hit marker change angle or drop//raise shield again quickly. Have a friend shoot with tranq darts or better from a distance to help speed up knockout. 140 or better will break metal shield before finished so carry spare.