So I've had this tank alt for a while but only recently starting doing some competitive Undaunted delves to really test him out, which is going fine I've had minimal issues staying alive and keeping most things focused on me. But I've just got 1H&S to 50, and I assume Shield Wall is must-have for any half-decent tank, yet I have no idea how I would go about using it. Block all attacks for 5 seconds? Can't I just do that by blocking manually - which allows more precise timing - albeit at the expense of stamina. I don't know, I'm just not sure at what point in a battle I would activate it. So how exactly do all you experienced tanks out there use it?