I am making a 55 monk i know the build and how to use it but theres one simple question. Prot Spirit reduces damage at 55 HP to 5 damage per hit does this also include hex damage such as barbs or desecrate enchants?
Yes, it does. The only thing that it doesn't reduce damage for is life stealing (which isn't damage) and health degeneration (which again, isn't damage).
Head to cursed lands and you'll see this for yourself. Or just head outside bergen and see if the Necrid Horseman spawned...aggro him and a group of rangers at the same time and hold your breath, especially in hard mode.