because hex purge has mass aoe build into it hint magic explosion damage, with 90% trigger rate and combine that with 3x defiler (2 after you consume one) you cleared screen lol. bane has its benefit but since physical are nerf to the ground so its not as useful compare to live. compared to purge its not a good after some testing on ptr. again here you can use what you like, but demon on ptr is a waste of skill point. none of the aura / curse worth dumping 15 to 20 points into it, the odds you trigger curse just way too low. its a waste compare to getting 3 demons and 51% dr(blood oath). its no brainer here, its the reason why I dont pick physical any more unless they change it in next ptr. if not, with the current ptr patch magic es is the way to go. rather its bane or purge
I haven't played PTR, how many points into mastery do you need to run 3 defilers?