+8
In most FPS games, the highest difficulty is usually the most realistic. But for Halo, it's probably normal or heroic because you need to consider the awesome armour they gave you and how effective plasma would really be on it to determine which simulates evolved combat best, amirite?
read the books
I have. Mk VI fluctuates in strength a lot. Different authors, ya know? Even in Legends, there's a lot of inconsistency.